3 way seps are ok but if you can achieve the listening experience you want with 2 ways, then you're better off. If you decide on 3 way seps, you have to consider the space they're going to occupy. You may need to bore more holes on your doors to accomodate the drivers, have custom door panels made for imaging / positioning the speakers, or even make use of kick-pods(& i have nothing against them :wink: ). If you go for the 2 way seps, you might not even need to sacrifice your door's stock grill. It all depends on you on how simple or complex your system will be.
I'm always amazed by peeps with simple audio setups but with sounds that are very rich and balanced. A agree with the guys above on auditioning different setups before you decide. At least by doing that, you would have a better idea on what system you want for your ride. :mrgreen: