I've heard some wonderful reviews, and I want to get a 15 or 18 and toss it in a 2008 Scion xB, will it get low in the right box? The amp would be right around 600rms to 1000peak. I love the lows, and the price on these is great. So if it's a good sub, 15 or 18? I'll probably be getting a better amp soon, of necessary.