I've replaced the dash speakers with 3 1/2 coaxial Pioneers w/ base blockers, and a pair of 8" Lanzar 3 ways in the doors. And yes, even with the inexpensive 8" Lanzar's, the S.Q. improvement is absolutely amazing.
At the very least folks...get some nice 3 1/2's in the dash.(guitar)
With the...