3-1/2" dash speakers the only answer?

[ash-man]

Has any one placed 4" speakers in the dash? or knows how to?
My idea is to take the dash out faburcate 4" rings made out of cherry and fiberglass mounted to the bottom of the dash under the 3-1/2 holes and place 4" componet speakers for better sound. i have years of fiber glass and car audio experince and none on the 300c's, but i dont want to mess up the car (it's new). i want every thing clean and professional thats why i choose 4" componet's there clean and professional sounding.. unless some one has an alternive with the same objective? my goal is to use after market navi-unit pioneer z2, 4" mb_quart componet's in the front dash(pvf-210),6x9 mb_quart componet's(RVF269) in the front doors and back dash(back dash w/boomer baskets), and a MB_quart RWE 8" sub in the back dash.. amp's MB_quart PAB 4100 4 ch amp for the inside speakers and dash and a MB_Quart PAB 2100 2 ch amp for the 8" in the rear deck..