Buick 2005 Rendezvous - Manual (Page 131)

If you have the luggage carrier with crossrails you can
load things on top of your vehicle. If you do load
things on the top of your vehicle, you must load them
on the luggage carrier crossrails. Some vehicles may not
have the crossrails.
Notice: Damage may be caused to the roof of your
vehicle if anything is placed directly on the roof.
Notice: Loading cargo on the luggage carrier that
weighs more than 220 lbs (100 kg) or hangs over the
rear or sides of the vehicle may damage your
vehicle. Load cargo so that it rests on the slats as
far forward as possible and against the side
rails, making sure to fasten it securely.
When you carry cargo on the luggage carrier of a
proper size and weight, put it on the slats and distribute
the weight evenly. Then slide the crossrail, if equipped,
up against the rear of the load to keep it from moving.
You can then tie it down. Cargo containers must
be loaded on the crossrails only.
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