I will be going sealed, space is everything. I had decided on a single 10 inch type R with an Alpine 400 watt amp for $150 shipped. I know the R's need more than that, and that they don't sound good in small sealed boxes. My trunk is 11 inches tall all the way across. There is one spot where it is about 14 inches tall, 20ish inches wide, and about 5 inches deep. Therefore, my box will be 13 inches tall, 20 something inches wide, 4 inches top depth, not sure on bottom depth, probably will match the angle of the back seats. I know that doesn't leave much mounting depth. I haven't built a box before, but think I can do it. Any suggestions, I know I can find a decent amp to match the sub, just need to determine what sub I need. I thought about a pair of 8's, but that would run into more money than the single 10. I was looking at the ED SQ10 pushed by a Kicker zx300.1 amp, total of under 200 bucks, leaves enough to build a box and the amp kit for less than 300, but then I heard that Elemental designs was crap, so not sure now. Thanks everyone.