I'm selling my grand prix this week. They have 2 15'' MA audio's which the guy wants and im selling those with the box and a hifonics 1206d amp for $600. I planned on keeping them and getting a better amp but he gave me a good offer. I'm getting a soundstream trx2000 amp for cheap and plan on having another$350 to spend on subs. Looking at either 12's or 15's. Which ones would you recommend with what box. I want something that can hit harder than my MA Audio's and sound a lot better. Room is an issue kind of, these are gonna go in a jeep cherokee but I don't want to fill up the whole back, but if its so much better having a bigger box with 2 15's than I'll just do it.