Buick RIVIERA 1993 Manual page 211

A
CAUTION:
Rust or dirt on the wheel, or on the parts to
which it is fastened, can make the wheel nuts
become loose after
a
time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
the places where the wheel attaches to the
vehicle. In an emergency, you can use a cloth or
a paper towel to do this; but be sure to use a
scraper or wire brush later, if you need to, to get
all the rust or dirt off.
Remove any rust or dirt from the wheel bolts, mounting
surfaces or spare wheel.