Pontiac 1999 Montana Owner's Manual page 174

Reposition the tiedowns by turning them
counterclockwise, then slide them along the side rail.
Turn the tiedowns clockwise to tighten them in place.
If you wish to attach the luggage tiedowns or other
compatible bicycle or ski accessory racks to the
crossrail, use the adjustable tapped plates under the
bumper strips.
2-78
Use the adjustable tiedown
loops in the side rails to
help secure large loads.
Lift the end of the bumper strip with a flathead
screwdriver and cut off enough of the strip to access the
tapped plates.
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