i live in illinois, what oil/viscosity do you guys recomend. what plugs do you recomend. and finally, do i need 3 cats on my car?i would like to upgrade my exhaust but the thought of 3 cats is a little too much money plus the cat-back good stuff. and while we're at it, i would like to use some lowering springs(eibach or whatever)but no one mentions or has available,dropped spindles which in my opinion, is the correct way of lowering the front and not mess with the camber,caster,etc. what's your opinion on this topic? thanks!