Buick REGAL 2011 Owner's Manual page 317

The vehicle cannot be dolly towed
from the rear.
Use only lukewarm or cold water, a
soft cloth, and a car washing soap
to clean exterior lamps and lenses.
Follow instructions under Washing
the Vehicle later in this section.
Occasional waxing or mild polishing
of the vehicle by hand may be
necessary to remove residue from
the paint finish. Approved cleaning
products can be obtained from your
dealer.
If the vehicle has a basecoat/
clearcoat paint finish, the clearcoat
gives more depth and gloss to the
colored basecoat. Always use
waxes and polishes that are
non-abrasive and made for a
basecoat/clearcoat paint finish.
Foreign materials such as calcium
chloride and other salts, ice melting
agents, road oil and tar, tree sap,
bird droppings, chemicals from
industrial chimneys, etc., can
damage the vehicle's finish if they
remain on painted surfaces. Wash
the vehicle as soon as possible.
If necessary, use non-abrasive
cleaners that are marked safe for
painted surfaces to remove foreign
matter.
Exterior painted surfaces are
subject to aging, weather, and
chemical fallout that can take their
toll over a period of years. To keep
the paint finish looking new, keep
the vehicle garaged or covered
whenever possible.