Almost never - only in extreme parking circumstances. Never at home - and my driveway is sloped downward a little, too. The VX transmission seems very heavy-duty and doesn't seem to mind. It would probably be a good idea for me to use it, but I don't.

The wife's A3 with the DSG transmission seems to get a lot of strain on it when doing the same, but she doesn't use the parking brake despite my suggestions.

By contrast, I ALWAYS use the parking brake on the 928... I saw Risky Business, and I learned my lesson!