Ok i have not the first clue about anything to do with car audio. I have the most basic system (i think) with just the 1 cd player and i think 4 speakers. I wanna replace all of the speakers. The question I have is what to replace them with. I've tried doing this on my own but there's coaxial systems component systems...speakers of all different sizes. Sorry if I sound like the noob i truly am at this. please help

 

from what i understand the 5x7's and the 6x8's are direct fits, you can use either, however for 6.5's and componet systems i believe you need an adaptor plate.

 

yea, just get two pairs of 6x8's (or 5x7) they will drop right in.

 

I just cut out my rear deck with a dremel and installed 6x9 Infinity's.
Much better sound than 6x8.
I also got an amp between them for my 2 12' subs.