I like SEM products the best myself, and have used them on various pieces inside my car. (in fact, I am doing some more today!)The down side is that they will get scratched and reveal the color of the plastic beneath. If your panels are really chalky and dried out, this will happen fairly often, so it is best to start with panels in good physical condition. Anyhow, I will caution you that you need to clean the hell out of them with some Simple Green and scrub them lightly with a green kitchen scrub pad as well. I would follow that up with a little bit of prep solvent on a rag to soften the plastic and promote adhesion. Any carpeted sections need to be scrubbed clean with a brush first, then hosed out and allowed to dry. As for the Velour, I don't know what to tell you. Depending on which upper panels you have, the best choice may be to get some black vinyl and redo them. The easiest ones to upholster would probably be the Cutlass Brougham/Salon deluxe uppers as they only have a piece of fabric glued to some foam and then glued to the board. The pull strap panel then bolts on top of that and squishes it down. Eliminate the emblem and it would look pretty generic.
As for where to get SEM, I get it at my local Finishmaster auto body supply store. I buy it in quarts, pints, gallons, etc. to be sprayed from a gun (I paid $50 for a quart of dark blue 2 days ago.).You will need at least a quart to do the job, but it may take two. It may also come in a spray can, but I am really not sure. I would also tell you that you should have the dye matched to the interior trim code of the Grand Prix donor car, and not just a generic black. Most 90's cars used some kind of charcoal color and not pure black, so the seats would probably look slightly lighter than the rest of the interior if you used a generic black. I would do the same when ordering the carpet kit. The headliner will probably just end up black as the color choices for headliner materials can tend to be quite limited. Here's a little tip for ya: Look through the Sunday paper, and the fliers that come in the mail for the Jo-Ann Fabrics ads. They sometimes have a 40% off on all yardage coupon, which is a substantial savings. I paid $20 for 3 yards of headliner fabric. You would need that, plus about a yard of black vinyl to do the job. Get about 3 cans of 3M general purpose upholstery glue from Wal Mart at a cost of $10 each. I would also go ahead and buy about a yard of 1/4 in thick open cell foam to complete the doors as well.
For the trunk, What I am doing is buying a bulk roll of cheap carpet in either dark gray or black for $10, and then gluing some jute sound deadener to it with the 3M contact cement. It will then be cut to size using an original trunk mat as a pattern. For complete trunk kits, you can either roll your own (I am going that route because I am poor), or buy one from one of our vendors. There is one vendor at the bottom of the forum index that specializes in them. It looks like some nice stuff, and the price is not bad when you consider how much time it would take to make it all yourself. If you do plan to build all your own panels, expect to spend 5-10 hours getting everything just perfect. The floor carpet is an easy project to do yourself and will take about an hour or so if you do it my way. It is the side and back panels that take the most time.
