Actually I'm not putting it in the seats, I want them under the seats, In the Carpet... As for the size, I think E60s used 8" subs. I will go and see if I can get the OEM E60 subs at junkys. They are Dual Voice I hope right? if not, Ill get theese Subs I guess. Not too much 6"s anyway...
Thanks very much, I searched and found this:
Hifonics HFi1000D Class D Amplifiers at Onlinecarstereo.com - Only this had 1ohm rating.