Hey guys,
Also just installed an Alpine CDE-121 in my 2003 Envoy XL. Same problem, the factory dash/radio bezel opening for the radio is just slightly too small to make the trim ring fit when you use the mentioned install kit (with the extra compartment beneath the radio). I imagine this could be the problem with many head units and not just the Alpine.
Just to be clear for anyone else running into this problem, the problem is that after installing everything, when you try to put the trim ring on the aftermarket head unit, the trim ring is too wide at the top corners to fit properly into the space.
The bad news: Yes, you'll have to modify your aftermarket trim ring.
The good news: This is actually a pretty simple thing to do as long as you approach it the right way.
Here's what you'll need: A tube of plastic epoxy, some 600-800 grit sandpaper, some fine 1000 grit wet/dry sandpaper, flat black spray paint.
First, you're going to fill in the corners you'll be altering with the epoxy. You're doing this so that there's still plastic underneath once you grind off the original thin black plastic of the trim ring. Follow the instructions on the epoxy carefully and make sure not to have bubbles in your epoxy when you apply it, otherwise you'll end up with small pinholes when you sand down to the epoxy later. When you apply it, just apply it to the corners you'll be altering and make sure not to spill any on the sides. Also, don't put too much on the top or your trim ring won't sit flush. It's best just to fill the empty space up, wipe off excess so that it sits flush with the trim ring.
Once the epoxy has fully set and hardened, use the coarser of your 2 sandpapers to start shaping those top corners down. In my case, I needed to take off the corners and also slightly taper the top end of the trim ring. Once you have your desired shape, check the plastic for pinholes and divots. If there are any, you can use body filler or any similar product to fill in and sand down those small holes. I used a tube of Bondo Glazing and Spot Putty. You could probably use more of the epoxy, but I thought that would be too messy.
I would not recommend using a belt sander or grinder to do your shaping, as that usually tends to burn plastics.
So once you've sanded your trim ring to shape, check it to fit before going any further. Make sure it fits on the head unit, that the face plate sits properly, and that there are no fitment issues.
Now you can sand the whole trim ring with the 1000 grit paper. Dry sand it first, and then wet sand it to make it nice and smooth. You need to make sure you've sanded your whole trim ring thoroughly or the paint won't stick to it. Clean off the trim ring thoroughly after you're done sanding it.
You're ready to paint. Here, I leave it to your discretion. I chose to go with the original flat black, so I bought a can and did that. You can choose whatever color you want, however I would recommend using a primer if you want to go with anything other than black or if you're concerned about the paint sticking to the trim ring. Also, it's best to use masking tape to tape over the little clips on your trim ring. Painting over these clips could cause fitment issues, not to mentioned rubbed off spray paint on those clips when you install and uninstall the trim ring.
When you paint, hit the trim ring with small soft spurts of paint, making sure not to go over the same spot twice. Don't hold the nozzle down, or you are guaranteed to get runs in your paint.
Make sure to let the trim ring properly dry before you handle it. If you don't really like the soft feel spray paint generally tends to leave, try putting a coat or two of car wax on the trim ring. This will shine up the dull look and also protect your paint, while providing a 'shell' that you feel first, instead of the paint.
Here's some pictures of my finished product, and also of the back of my trim ring with the epoxy filled in. If for some reason your trim ring is rather large and the whole side needs altering, I would recommend filling the entire sides of the trim ring in with the epoxy.
I guess I could always ISO-MOUNT the SINGLE-DIN radio so that I do not need a trim ring. Thoughts?:undecided
