GMC SIERRA 2020 Owner's Manual page 431

430 Vehicle Care
Automatic Car Wash
Caution
Some automatic car washes can
cause damage to the vehicle,
wheels and ground effects.
Automatic car washes are not
recommended, due to lack of
clearance for the undercarriage
and/or wide rear tires and wheels.
Caution
Automatic car washes can cause
damage to the vehicle, wheels,
ground effects, and convertible
top (if equipped).
Do not use automatic car washes
due to lack of clearance for the
undercarriage, wide rear tires,
and wheels.
If using an automatic car wash,
follow with the car wash
instructions. The windshield wiper
and rear window wiper, if equipped,
must be turned off. Remove any
accessories that may be damaged
or interfere with the car wash
equipment.
See Power Assist Steps 0 34 for
cleaning information.
Rinse the vehicle well, before
washing and after, to remove all
cleaning agents completely. If they
are allowed to dry on the surface,
they could stain.
Dry the finish with a soft, clean
chamois or an all-cotton towel to
avoid surface scratches and water
spotting.
Finish Care
Application of aftermarket clearcoat
sealant/wax materials is not
recommended. If painted surfaces
are damaged, see your dealer to
have the damage assessed and
repaired. 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.
Occasional hand waxing or mild
polishing should be done to remove
residue from the paint finish. See
your dealer for approved cleaning
products.
Do not apply waxes or polishes to
uncoated plastic, vinyl, rubber,
decals, simulated wood, or flat paint
as damage can occur.
Caution
Machine compounding or
aggressive polishing on a
basecoat/clearcoat paint finish
may damage it. Use only
non-abrasive waxes and polishes
that are made for a basecoat/
clearcoat paint finish on the
vehicle.