I'm thinking of getting tweets on the pillars, 6.5in coaxial (not sure how many ways) or just 1way woofer front speakers, replace or remove the 4in rear speakers (if i do replace them I'd turn them quiet but just loud enough to slightly brighten the subs) & 2 8in subs. I love rock. What is your opinion on my set-up? Coaxial vs. Component, Advantages & Opinions?
best sounding IMO are coaxials down & low (doors or kick panels), or components in the same location with the tweeters mounted near the midwoofer.
components will give you better midbass, but mounting the tweeter up high on the pillers is only a good idea if it sounds good to you (experiment w/placement before you drill).
whatever you do, i would advise against mounting a tweeter up high in addition to a coaxial system. you only need one tweeter per channel.