See also:

Parking the vehicle for a long period
If you leave the vehicle parked for longer than four weeks, the battery may be damaged by exhaustive discharge. Connect a trickle charger. You can obtain information about trickle chargers ...

Cleaning the trailer tow hitch
The ball coupling must be cleaned if it becomes dirty or corroded. Remove rust on the ball of the ball coupling, e.g. with a wire brush. Remove dirt with a clean, lint-free cloth or a brush. A ...

Roof carrier
Important safety notes WARNING   Only use carriers when the crossbars have been completely mounted. The left and right roof rails are only stabilized by means of the crossbars mounted. ...