I once owned a 2012 Genesis with Automatic Distance cruise control and while it worked well, adjusting speed to maintain a driver pre-set following distance, I did encounter a problem that caused me not to use it too often. I was following traffic in the middle lane on a 3-lane highway at about 65 mph with the cruise control set. A car suddenly cut in front of me from the left lane and my car went into an automatic emergency brake mode. The sensors had suddenly detected a rapid change in the distance to the car in front and braked hard to regain the set distance. The car following me had to take evasive action to avoid hitting me. While the car that moved in front of me had certainly 'invaded my space' it was not so close that it would normally have caused me to brake.

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1991 M-B 560SEL Arctic White/Grey 99,000 Miles
1987 M-B 300SDL Ivory/Palomino 229,000 Miles (sold but never forgotten)
2006 Volvo XC70 Blue/Beige
1999 Porsche Boxster Arena Red/Savanna Beige
1986 Porsche 928S Goldweiss/Brown