Going over large bumps in convertible models may cause the roll bar to deploy, rendering the roof inoperative. Special tools are generally required to return the roll bar to its stowed position.Google+
Car Problem Reports
Mercedes-Benz CLK320 Going Over Bumps in Convertibles May Cause Roll Bar to Deploy
Mercedes-Benz CLK320 Problem
Mind you when this happened the rear shocks were in need of replacement! I was in a "SPORTY" mood and went through a dip in the road a lil too fast. The rear of the car bounced and when in hit the ground. When it did the roll bars deployed and all the alarms went off in the car and a 911 call was places for me (thank you mb). The bang from the roll bar sounds like a gunshotand if that's not enough to scare the daylights out of you, the alarms will!. To put the roll bars back down, you need to put all of your weight into pushing the bar back down and, using a long flat head screwdriver, you need to feel for the locking pin and push it back into the locked position. The Pin is located below the rear deck on the right side of the roll bar. This ma take several attempts. Good luck!