so how do you control the empeg player? a remote control?

I was wondering the same thing. I've heard people talk about mounting the Empeg in the trunk, but I don't know of anyone who's actually done it.

I would probably just want to replace the head unit. Would there be any problems with that?

No, of course not. The empeg is designed to be your "only" stereo, and works best that way. The only issue is that in most cars you also need to install an amplifier since you won't be using the factory radio's built-in amplification any more.

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Tony Fabris