OK - very simple and (now) obvious fix. This is the procedure: Press the Info/Setup hardkey on the headunit, then "Setup/Bluetooth/Advanced Setup/Restore Factory Settings". This will "reset" the head unit bluetooth to factory default values. This procedure will also delete all existing bluetooth connections and all contacts you may already had in head unit, so beware of the latter effect as you may have to add new contact info if it is not already transferred onto your new phone. I then ensured I removed the VELOSTER bluetooth connection on my own GS3 phone. So now both sides should be "clean and unpaired". I then had the head unit seek out all bluetooth radios and then turned on the VELOSTER bluetooth "found" on my phone screen (obviously ensure bluetooth radio is "on" during this procedure. I entered passkey of 0000 when asked. Once my phone and head unit synched up, I received a "download contacts?" question on my phone, and I said YES. Some phones for the GS3 will have this question come up on the head unit, so be aware of this difference - just be very attentive. Press YES upon this question. Within seconds, all my contacts transferred to the car's head unit (without a confirmation, by the way). Entire procedure sitting in drivers seat doing all of this took all of 3 minutes from beginning to end.
Try the above exactly and report back.