the majority of home speakers are 8 ohm

the majority of car speakers are 4 ohm (subs being a pretty big exception - you'll see 6 ohm DVC, and some 8 ohm as well)

I originally had the A600 bridged running into 3 jl audio 8w6 (DVC 6 ohm speakers) - running the 3 in a parallel-series config yields about a 3 ohm load .

I'm only gonna be putting one jl audio 8w6 back in my new car. Is the A600 overkill for one 8" sub? Probably, but:

1, I already have the amp
2, I'd rather have power sitting in reserve than not enough, which would overdrive my amp causing harmful distortion
3, according to jl's web page the 8w6 can handle 250 watts per voice coil so maybe it'll do just fine - we'll see.

Road noise is a major enemy to car stereo's.

Tony, I don't see how you would have enough room to mount a center channel speaker up near the sunglasses holder.

Ben