Dr. Bob's Stereo Install - '94 premium audio -> Nav/Carplay/backup cam

First step was gutting the trunk. This wasn't too hard, you just find all the plastic interior clips and pull them out. Then, the carpet comes out and after that is a layer of jute padding, or as someone called it, pressed lint. Also found below the carpet was this little pressed board thing for support at the edges of the trunk - I seem to be missing one and will have to make a new one. After many, many hours of cleaning, vacuuming, spraying with various cleaners, etc. I now have a clean trunk. Time to get to work!

To install the backup camera, I pulled the center panel out. For the Kouki lights, you can leave the tail lights in place, I have heard that for pre 1994, you have to pull the tail lights to remove the center panel. I just pulled up the rubber gasket and found two screws and pried the center panel at the edges. Then, I removed the lighst from the fixtures and let them dangle.

I fooled around with the license plate lights for a while to find a decent solution and this is what I came up with - you may find a better one. I loosened the three screws that hold the fixture in place and slipped the RCA connectors through the gap and fished them up to the space behind the center panel. From there, I pulled out the grommet that protected the backup light wiring and went to work opening it up enough that I could fit the RCA connectors through it. This was difficult because the grommet only has very small holes for the four wires that go through it. I ended up cutting the center out and pushing the connectors throug it and reseating the grommet.

Then I secured the camera to the center of the bumper just above the license plate using 3M double sided tape - not foam type, but, some sort of heavy duty putty with adhesive on both sides that I used to attach an airdam on a previous car.

On the inside, I used a multimeter to identify the ground wire on a backup light and I inferred the other must be power. I used a clamp on tap to connect to the power line and a spade connector for the backup camera line. I know some people don't like this method, but, it works for me. If it fails, I can repair it.

Next up, pick a grommet that the ECU uses and push the connector through there and feed the wire into the engine compartment. The question is which side to go down and the answer required looking on the interior behind the carpet.

Lots of disassembly here. Start with pulling up the smuggler's boxes and removing the three screws. Then, pull up the door sill enough that the side panel can be pulled loose. On the driver's side, you have to remove the latch surround, it has a screw and then prys loose. Then you can pull the side panel off.



On to the trim at the top of the carpet. There are two clip/cover things here:

On the passenger side, there was a coat hook secured with a bolt, the other side was just a simple cover. For both, use something to pry the plastic up and undo anything underneath - for me, one bolt under the hook.


The cover is held in by clips. and looks like this. Below the cover, there are 4 (mine only had 3) plastic circular press on fasteners.

Now you can pull the carpet back. Oh man that is a LOT of jute! I have a bunch of sound deadening material - heavy foam 1 cm thick that is shiny on one side. I plan on using that on the interior. I also bought some of the heavy dynamat type material (like heavy stick on asphault) Not sure if I will use that or maybe only selected places. If I do, should I remove the jute or thin it or just let it be and compress it when I put the carpet back?

I left the first picture full size so you could bask in the glory that is thick jute . . .


I also see three pass throughs, left, right, and center. I looked on the engine side and the most easily accessible pass through is probably the drivers side - that is what I chose. The grommet is very secure though and will requrie making a secondary hole to pass the RCA connectors.

I pushed the wire through a grommet near the ECU and routed it along the perimeter attaching to a major harness with zip ties from time to time - particularly at large bends. Then, I had to remove the airbox - would have been easier with a 'cold air intake' (which I replaced with factory airbox). Then pushed the wire through the grommet to the interior space.


I also removed a rear speaker - they look pretty rough, so I am going to replace them while I am at it. It has three bolts and a wire. If you replace them, you will want a harness or scavenge the harness from the existing (or throw your hands up and rewire the whole shebang). You can also see the amplifier in there.

NOTE: Before I finsihed up the trunk, I used a multi meter to verify that all the contacts were good. This turned out to be a good way to identify that my electrical scheme didn't work as well as I hoped. I stripped a bit more and fed the power wire directly into where the reverse light power connects. Ground went to a nearby bolt already in use as ground.



I rechecked everything and it was okay. Then I used zip ties to route the wire along the rear light harness and to the trunk firewall and secured the excess bundle with zip ties.





Then, I fabricated replacement side board pieces from whiteboard and gutter clips from home depot. I thought about replacing the fiberboard that goes at the front of the compartment to protect the ECU, but, it is only held in place by those plastic push clips, so, I just reused the old one. I ended up putting a sheet of the heavy sound dampener in the middle of the bottom of the trunk. I did this because it is directly over the muffler and I want to not worry about any related drones or rattles. Hopefully it removes any weird resonances.

Then, reassembled the carpet in the trunk and put the factory air intake back and get to work in the cabin.



In the cabin, I want to quiet it down a bit, but, I am not planning on going whole hog ann double layering everything. So, what I did was used some ~ 344 mil foam for most of the firewall except the raised area in the center which I used butyl mat (dynamat stuff) to bridge and cover any gaps. I used the thin mat here just because the firewall is raised here.


Last, I replaced the rear speakers. I ended up desoldering the old ones from the connector and soldering the connector to the new ones. I reused the metal frame and everything goes back just like stock. It was difficult to get the frame out because two of the fasteners are just underneath the trim piece just above the speakers. I invented a couple new words, but, I got it done.

I decided to put some dampener in the space behind the woofers, so, to do a good job, I removed the woofers. First, release the carptet which is held in place by these plastic clips. Then remove the speaker grill held by 4 push clips. It is held pretty strong, I used an interior pry bar.




The next step is removing the 6 bolts with 10mm heads. Then wiggle the speaker box until you can see to unclip it. Then you can get the box out. I removed the 4 screws, but it really didn't do me much good at this point. The speaker wires are well connected. As you can see, I have a good news/bad news situation.


The bad news is that my woofers are completely shot. The good news is that I found this out at the easiest time to replace them. Also, I found a missing plastic fastener under a woofer box, so, good things for sure.


Then sound dampener on the back and also on the two flat pieces in the very front to stop any potential resonances.

Really helpful information thanks. I have just fitted a Sony head unit to my MR2, also just bought a reverse camera that I'm going to fit shortly so gives me a good idea on where to route the wires etc. Planning on some sound deadening while I'm in there as well.

I recently replaced the woofers in my rear subs as they were also completely shot.

We’ll, that was a bust. There is no amount of filing, tin snipping, grinding, or what ever else that is going to make these woofers fit. DON'T BOTHER WITH TANG BANDS. The holes don't match up - which I did not figure out until after grinding the rim to nearly nothing to try to get it to seat on the enclosure. It won't seat properly because the magnet is too big and hits the inside of the enclosure. I tried to gently massage the insides of the enclosure, but, I don't want to ruin them, so, I just don't think these speakers will work. Maybe I used these in the doors and get some components.

I think I am on to something. There was a fiberboard ring between the speaker box and the wall of the box. It went as shown in the first picture. If I remove it and place it between the speaker enclosure and the speaker - the second and third pics, I definetly have enough space for the subwoofer. I checked fitment in the car and it seems to fit, it just moves the face of the speaker closer to the speaker grill. And since there is a grill in place, everything is protected. I will give it a try tomorrow and report back. I will need longer screws though.

I wasn’t on to anything. The ring protects the speaker surround - I checked with my old speakers that no longer had a surround.


Back to the grindstone

Helpful hint - lay out a white paper towel. You will be going through a lot of cutoff wheels with your dremel if you go this route (and honestly, I couldn't make the tin snips work - the metal is too thick and my snips are not great). The paper towel makes it easy to find all the useful tools when you swap cutoff wheels and it is a great place to wipe the blood when you stab yourself with the wrench/flathead multitool

After much grinding, swearing, fitting, grinding some more, I got it to fit with only one screw not working out. This is the passenger side and there is some plastic that makes fitting a bit hard because the magnet is so much bigger. I could have done better, but, I had to learn somewhere. Also note, do your learning on the passenger side so you don't have to live with the errors right next to you.





Closeup of the work and now back in place




For the next speaker, I took more time thinking about and looking at the setup to better understand what caused so many problems. 1) The fit is very tight as seen in this pic below with stock speaker. 2) the screw holes are elongaged and larger on the stock speakers than the Tangs. 3) when cutting, you do have to get uncomfortably close to the speaker foam - make your peace with that and have a steady hand. 4) I did a lot of attempts to try to match the images online where they cut most of the metal frame away. This time, I traced the stock onto the face of the Tang very carefully (much more carefully than I had on the first go). I made sure that the screw holes were as lined up as I could get them and I made sure the lines I drew were as tight next to the stock speakers as I could get them. No pic of the marked but uncut Tang (sorry). Then, I went straight to the line and cut off there. I cut off large pieces this time, where I had many small pieces last time - Aim to cut off large pieces. In the next picture, notice that there is a sligth silver around the edge? That is my silver sharpie markings and guess what? it was not quite fitting. You really really need to get it close. So, I spent some time grinding the edges until no sharpie showed. Finally, I used a reamer bit on the dremel to open up the screw holes in the directions necessary to get the screws to fit (I test fit it and judged where to open up the holes).





Final fit and it is done. The second speaker was a lot easier and a lot faster than the first one.