The ETA issue can be resolved by getting the dealer to recode back to your car. I have this issue right now as I loaded the beta version but have changed it a number of times to implement martin's great work. Will get dealer to recode nav to my car.
Sure you all know, but to ensure you dont lose the RDS features (UK) switch off the radio (left knob button) and back on again BEFORE pressing OK to reboot the nav at the end of the upgrade.
This maintains the RDS and INFO features.

Thank you Martin for your work

Steve