I did it. Built the box, sealed it with acrylic all around, and bolted in the subs. I hooked it up to an out of the box Alpine mrp-m350.

I went from 8 loyal months with a plate to a 3 cu ft enclosure, and I like it. It sounds much clearer at every volume. With a plate, there was three volumes that varied for song: too low to hear, just right, or too loud and sounds like farting. With the sealed enclosure, at every volume, the bass sounds great. It fits the music, and is very tight. I haven't messed around with it at high volumes because I finished hooking it up at 10:00pm.

I still believe the plate has some positives, whether or not musicly. On a plate, the whole car vibrated, it felt like the speakers were under you're seat. The trade off, most the bass in songs sounded like farting. That is the best word to describe. If anyone ever played a bass guitar and tried playing all strings at once, thats what it sounds like.

All in all, I'm glad I built the enclosure, and I'm looking forward to cranking it after work.

Sealed for the win

Seriously though, I'm glad you like the results. If you want the car to shake a little more when the subs hit try bolting the box firmly down.

Wheres a good spot to bolt it?
Is it alright just to bolt it to the body?

there were already a few holes in the bottom of my well, under the carpet. i just took a couple measurements, and stuck a threaded rod i got from lowes through, bolts top and bottom, some small poly bushing i had sitting around and a bit of silicone.

i did it more to prevent someone from taking the box out of my car than to get the car to shake.

I plan on drilling holes in the bottom of my well to bolt the box down primarily to prevent theft. Also using all kinds of cool screws, some of which haven't been around for a while (go go 60's holly butterflies) to hold the subs down. After I weld in the cage the rear seat is going to be next to impossible to get the amps out of.