i'm looking into getting a Alpine Ai-NET receiver and the alpine iPod adapter that allows the receiver to be the interface for the iPod. I went to Myer Emco (car audio store) about installing the system in my car but keeping my factory speakers. They said they could do it but i would lose my factory sub woofer. I'd like to keep my factory sound as much as possible without upgrading my whole system. What are my options? (Don't exactly trust the guys at the store)

 

Hmm, makes sense in a way. If I'm right, I think this is what they're thinking: run your front and rear speakers off of the Alpine head units internal amp, thus bypassing your stock amp completely. However, your stock sub is powered by the stock sub amp (I presume) and this is where it gets messy.
They could probably figure out a way to send a signal from the alpine to the stock sub amp, however I doubt the alpine could power 4 speakers (plus 2 tweeters in the SC) AND the sub by itself. The only other option left would be to go the aftermarket route for a sub amp and then you might as well get a new aftermarket sub anyways, since most aftermarket stuff will knock the socks off the stock components.