Well, 2 days with G2 (D802), stock firmware, not rooted. The car is Audi A8 2010, MMI 3G+ with online services.
There is native rsap support. Everything works just fine - fast pairing and connection, phonebook transfer, phonecalls and internet. Didn't try sms, but I don't think it has any specific issues. So there is a chance that other models like D801, D803, etc. are rsap compatible too.
Basically I can say that the phone is very good - fast cpu, nice screen, beefy battery, rsap support (sorry admin