I bought a Bluetooth kit from Eddie-NL it works with the RNS510 but does not display on the highline and I can't answer the phone with the steering wheel button but I can still answer the phone through the stereo and stream music through Bluetooth.
I wanted the kit as it was compattable with iPhones, I think you get the phone menu on the highline display if you buy a polar fis box but not 100% sure.
Eddie was also much cheaper then the kits advertised on eBay.