4x6M up front, 6.5" rear.
I have Alpines in my SDL, decent for what I paid. Rears you will have to modify some as they're a metric size factory. Fronts drop in.
If you have the patience, clean up the wiring behind the dash and install a nice small amplifier. 30-50x4 will blow your mind in sound quality.
I'm not a doctor, but I'll have a look.
Eight others from BMW, GM, Ford, and Volvo.
Liberty will not descend to a people; a people must raise themselves to liberty.