Hello All! I have every intention of purchasing an A5 in the next six months. The money is saved, colors chosen... there remains one uncomfortable detail. The head unit. This is not a deal breaker for me but a matter of "completeness" going in to buy this vehicle. I am an audio and tech enthusiast and I want to put in my own head unit with GPS capability. I intend to get the B&O system from the factory and after a year or so upgrade the head unit to one that has touchscreen, high fidelity, built in EQ, navigation, etc. I have decided not to spend the extra 2k+ on the audi nav system because of several reasons, not the least of which is price and its expensive (vs. free) upgrade ability. So, the question is this: Can I change the head unit without messing up the MMI system and or pissing off the car's computer in general? I'm begging anyone who is an owner or who knows the inner workings of the MMI/Audi Symphony systems to offer their advice. It would be much appreciated.