Chipping / xenons, Sat nav and stuff? Wisdom required.

Chipping (or remapping) a car is really dependent on the condition of the engine, and the car as a whole. If it's been well looked after, with clean oil and a good power output in standard trim a remap will be fine. A good tuner will check the car over and advise you of this.

I'm not totally sure if the RNS-D shows a compass on-screen, but my RNS-E provides a compass in the DIS display, between the dials (simply N, NE, E, SE etc). You can upgrade the software with the latest maps, but you cannot add POIs like speed camera locations. It's just not possible right now unless Audi release a DVD with this included.

Bluetooth is no problem - in fact, you can fit Bluetooth kits to all models regardless of the stereo fitted. There's an interface to all of them.

You can change the sidelights to match the Xenons more closely, although they're not perfect. I've done this on my car by fitting Philips Blue Vision sidelight bulbs. They're about a fiver delivered from eBay. Note that blue LEDs will work but will show a bulb failure warning on DIS, thanks to their lower wattage.

Hope this helps!

But you can fit LED bulbs without having any problems, PIAA do some and they're the same W.

RNS-D does show a compass on a separate screen, press the right knob when on the map screen and it will appear!