My Denali has ACC, I used it 3 or 4 times and didn't care for it, so I turned
it off and it is now regular cruise.(GMC has an override)
My bud bought a new Audi last fall, it had ACC and he had it set at
60 KM per hour, car in front slowed down and then quickly stopped, his
car was unable to stop and he bumped rear of stopped car.
He called Audi and they sent two people out to check his car. They took
readings from his on board computer and left.
Two weeks later he received a phone call advising him that ACC only
works at 40KPH or less. Go figure.
He was going to pursue further but while on vacation the car was
stolen from Pearson airport.
He bought a new Audi and 2 weeks later received a call that his first car
was found in a container in Montreal. He informed Police it belonged to
insurance company.