I have a 1998 240sx that takes 6.5" in all 4 corners. I currently have Infinity reference 5 1/4" components in the front. And some cheap ass lighning audio 3ways in the back. I got a great deal on the Infinitys cause they were smaller. I got the adapter rings free. I got the rears cause they were the cheapest shit I could find and the rears were blown too. Now they are buzzing. The Infinity's seem to need more power to get better bass out of them. I want to move them to the rear. Get a 4ch amp and get some nice 6.5" components in the front. DIAMOND AUDIO M661 is the only thing that has been recomended so far. Ideas?