TacoTunes also has a system that integrates in with the factory head unit.
Just about anything is an upgrade over the factory stuff.
I'm running JL Audio: Fr to R - 3.5, 6x9, 6.5, 6.5, 2x 8" (w3's, have a single 10 in the works). It'd be much better with an aftermarket head unit for sure, but a...