There were a few complaints about some parts of the RNS 510 but I can't find the thread but some of the issues have been resolved with a new firmware version. Some of the new and upgraded features of the new firmware are

Bluetooth audio support
AV output
Faster touchscreen response
New volume location at bottom of screen without any dimming
Bluetooth Audio Support
New Balance Fader

This also upgrades the units to version B which you need if you want to have features like AC controls via the RNS510 (need an upgraded climatronic controller). Be warned that you could brick your RNS510 and you will have to reload your maps (last locations and so on are still kept) and your music as the hard drive is formatted.

Instructions are on my website and I'll post updates there on firmware download locations etc.

http://www.my-gti.com/497/volkswagen...o-version-1100