If I went with a 6, I could maybe get the cover to go back into place and keep the look clean. Granted it may or may not be a rattle issue, but as a family car I don't want an exposed 8" woofer in the rear where groceries, heavy items, bags, toys, etc may be flying around.
If I were to go with the JL audio 6.5" (depth is about 4"-5" and 6w0 only needs 3.5") and built this out of fiberglass, where do I start? Also, I assume the fiberglass would then be a permanent part of that compartment as I can't see how I'd get it out. If so, I'd want it to look at clean as possible. I've bookmarked a few fiberglass websites but if you can pass along any tips that would be cool. Great job on your box btw. I also need to know where to get all the supplies, fiberglass, bondo, fabric, baffles, etc.
My overall goal, while wanting full, clean rich sound is minimal or zero intrusiveness. I don't want a sub box taking up room and I can't have exposed amps or woofers. So, any way to have a sub in that compartment it would have to be hidden and protected. Ideally, I'd use the same cover.