The data I found concerning engine shipments for the SRT line was for 4800 engines. Now I am sure some of those went to dealerships or were held back for warranty work in case of a failed engine. MB had discontinued putting that engine in anything of theirs, so I would assume they went there for the XF builds. It was an article in German about the Karmann factory's last days of building Crossfires. They were also well known for their design and build of the hide away roadster tops. Still good information though.