They should take them back they are the wrong material and too long to attach the "baffle covers". The correct Mercedes Benz number for the aluminum bolts is N000912005010. Metric size is M5-0.8 X16 MM. The site below has excellent tips for the M112 engine used in the Crossfire, paragraph 3 deals with the covers and baffles on top of them. The sealant is available at Needswings.com. Foreign Motorworks' Car Tips