Vehicles with side airbag:

CAUTION: Note safety measures when working on airbag. See appropriate Air Bag Restraint Systems article in Restraints.

For vehicles with coded radio unit/radio-navigation system (RNS) note coding; ask if necessary.
Disconnect battery ground strap/cable and cover negative pole.
CAUTION: On vehicles equipped with Audi Telematics by OnStar®, switch-off the emergency (back-up) battery for the Telematic/Telephone Control Module prior to disconnecting the vehicle battery. See EXAMPLE: SWITCH OFF EMERGENCY (BACK-UP) BATTERY . Switch-on the emergency (back-up) battery after reconnecting the vehicle battery. See EXAMPLE: SWITCH ON EMERGENCY (BACK-UP) BATTERY .