Pontiac 2001 Aztek Owner's Manual page 152

NOTICE:
Loading cargo that weighs more than 220 lbs.
(100 kg) on the luggage carrier may damage
your vehicle.
2-68
Don't exceed the maximum vehicle capacity when
loading your vehicle. For more information on vehicle
capacity and loading, see "Loading Your Vehicle"
in the Index.
To prevent damage or loss of cargo as you're driving,
check now and then to make sure the luggage carrier
and cargo are still securely fastened.
Your luggage carrier has release levers within the end of
each crossrail support.