I HAD ADAPTIVE CRUISE ON, WAS AT A STOP LIGHT, SO ADAPTIVE STOPPED, THE TRUCK IN FRONT OF ME MOVED BECAUSE THE LIGHT TURNED GREEN, SO TO ENGAGE THE CRUISE I GENTLY GAVE IT GAS AND I FELT THE CRUISE KICK SO I MOVED MY FOOT AND THEN THE CAR LUNGED INTO THE TRAILER HITCH OF THE TRUCK IN FRONT OF ME. I HAD NO TIME TO REACT, THE CRASH WARNING DID NOT FLASH NOR DID THE BRAKING ASSIST ENGAGE. LUCKILY THE GUY I HIT WAS NOT AFFECTED THE HITCH PREVENTED DAMAGE TO HIS TRUCK BUT MY CAR TOOK ALL THE DAMAGE. I WAS SO SHOOK THAT BEFORE I COULD APPLY BRAKES MY CAR STILL WAS TRYING TO MOVE FORWARD EVEN THOUGH IT HAD HIT THE HITCH. THIS WAS ON A HIGHWAY JUST AS IT WAS MERGING TO A STREET. I CONTACTED CADILLAC/GM AND SENT THEM PICTURES AND 2 DAYS LATER THEY CALLED AND SAID I HAD NO CASE, THEY DID NOT EVEN SEND ME TO A DEALER TO CHECK OUT THE SYSTEM BY A PROFESSIONAL.