See also:

Reverse Gear Wipes
If the rear wiper control is off, the rear wiper will automatically operate continuously when the shift lever is in R (Reverse), and the front windshield wiper is performing low or high speed wipe ...

How the System Works
URPA comes on automatically when the shift lever is moved into R (Reverse). A single tone sounds to indicate the system is working. URPA operates only at speeds less than 8 km/h (5 mph). An obstacle ...

What Makes a Denali
The changes from a regular Acadia to a Denali are obvious from the outside, and they make the Acadia Denali look more put together, as if it were sculpted from one piece of metal rather than glued ...