Mercury 1999 Villager Owner's Manual page 170

Driving
LUGGAGE RACK
The front and rear crossbar can be adjusted to fit the item being carried.
Do not load more than 44 kg (100 lbs.) on the luggage rack.
To adjust cross-bar position:
1. Loosen the thumbwheel at both
ends of the cross-bar.
2. Slide the cross-bar to the desired
location.
3. Tighten the thumbwheel at both
ends of the cross-bar.
Use adjustable tie down loops to secure the load.
170