I know the answer to this question will be very subjective, but your feedback is appreciated. I have a stock system in my car right now. It sounds decent, but needs a little more impact. Is there a minor upgrade that will substantially improve sound quality. maybe just adding sub(s) under the seat, if that's possible with the oem HU. or maybe just upgrading the speakers. I don't drive a lot, but I wanna be able to hear sound consistently over the loud engine or when the top is down.

I just added a 30GB archos using the pie aux iput, so now I'm more motivated to improve sound. It would be a real shame to upgrade the HU after just buying the P.I.E harness.

 

headunit would be first , but if you don't like that idea , pick up a nice set of componets and a 2channel amp... if your planning on doing a sub later you can go with a 4 channel amp now and then bridge the rears for the sub later on.