I have been contiplating many upgrades, changing out the HU, changing all stock 5x7's and adding an amp, but all this gets up there in price for parts + labour to install. Just wondering if anybody out there has changed out the HU, added an amp, but kept all stock speakers and just added a set of tweeters up on the dash. Financially this can be done for alot less but do you think it could hold its own and actually sound good?