Cadillac 2007 DTS Owner's Manual page 332

If your vehicle is a Professional Vehicle, the
vehicle specific Certification label is provided by
the final stage manufacturer. The coach-builder
should be consulted if the final stage
manufacturer's label is not present. The Gross
Vehicle Weight Rating GVWR label should be on
the driver's door edge.
If you do have a heavy load, you should spread it
out. See "Steps for Determining Correct Load
Limit" earlier in this section.
332
CAUTION:
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Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
Notice: Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.