If you purchase the Foxwell in years past you could get two downloads for it for the initial cost. After that you can add more programs for up to I believe four makes on the one scan tool. That may help you with some of the other makes/models of cars you have. The Foxwell when scanning A Crossfire goes thru something like 25 system ( scanning as a Mercedes R170), but it can only find 18 or something like that when used on a Crossfire as the systems are different between the two cars. I have no idea what it can or can't find in the way of the roadsters roof; I would think the SLK hard top and the Crossfires rag top are different switch and hydraulically. I also have a 2005 CLK 500 and the Foxwell works really well with it, scanning something like 39 systems. Don't get the Chrysler down load as it is useless with the Crossfire; use the Mercedes. The Foxwell is a lot of tool for the money, but nothing like a DRB III emulator if you can figure out how to get that to work it seems to be the best, for the least amount of money.