It seems your Audi has different problems with different profiles... Does it connect to PBAP at all? Maybe it uses "Handsfree" when IrMC is not available?
Anyway, you have to find out why not all expected entries are transferred. There are two possibilities: the phone doesn't send them or the car ignores them. Create a log and look inside. If they are contained in the log, it's the car. Check if you can find a difference between the transferred contacts and the ignored ones. Look for special characters (e.g. QUOTED-PRINTABLE) or fields (e.g. pictures, memo, ...)
If they are already missing in the log try the "visible" option. Also some sync apps, like MyPhoneExplorer or some Exchange syncs create contacts database entries which are invisible for my app. Sometimes it helps to make sure all contacts are contained in a contacts group and select all groups individually.