Cadillac 2007 XLR Owner's Manual page 155

Your vehicle will not reach the set speed until the
system determines there is not a vehicle in
front of you. At that point, your vehicle speed will
increase to the set speed.
Decreasing Set Speed While Using
Adaptive Cruise Control
Press in the set/decrease button on the end of the
lever until you reach the lower speed you want,
then release it.
To slow down in very small amounts, briefly press
the set/decrease button. Each time you do this,
your set speed will be 1 mph (1.6 km/h) slower.
Resuming a Set Speed
Suppose you set your Adaptive Cruise Control at
a desired speed and then you apply the brake.
This will disengage the Adaptive Cruise Control.
But you do not need to reset it.
Once you are going about 25 mph (40 km/h) or
more, you can move the Adaptive Cruise Control
switch briefly from on to resume/increase.
Adaptive Cruise Control will be engaged with the
previously chosen set speed.
Selecting the Follow Distance (GAP)
When the system detects a slower moving vehicle,
it will adjust your vehicle's speed and maintain
the follow distance (gap) you select.
Press the top of the button to increase the
distance or the bottom of the button to decrease
the distance. The first button press will show
you the current follow distance setting on the HUD.
Your current follow distance setting will be
maintained until you change it.
Use the GAP button on
the steering wheel to
adjust the follow
distance.
155