Mercedes-Benz Vito 111 CDI/BlueTEC Operating Instructions Manual page 324

Carrier systems
322
Mercedes-Benz vehicles. This will help avoid
damage to the vehicle.
You can fit a roof carrier to the roof and, for
example, a rear-mounted cycle rack on the tail-
gate.
Fit the protective caps on the securing threads
after you have removed the roof carrier.
If you have fitted a rear rack on the tailgate, the
additional weight reduces the assistance provi-
ded by the gas pressure springs when the tail-
gate is opened. You will then need more force to
open the tailgate. At low outside temperatures
below freezing you will need to provide extra
support for the tailgate to prevent it from sinking
unintentionally.