Re: shopping for Crossfire
<sigh> Read 3-4 pages of each model's forum and you'll pick up a lot of answers. IMHO...
1-Mechanical parts are available but they are Mercedes parts with Chrysler markup tacked on. Some parts are available from Mercedes, believe it or not, cheaper than from Chrysler. Body parts and convertible roofs are generally difficult to find.
2-Seat heaters. Clunks in power train. Valve cover leaks. Peruse the forum for questions about problems.
3-Neither seem unreliable, but the occasional reported problems are not cheap to fix if serious. Other than the MT6 being difficult to shift from 1-2, most everyone is happy with their transmission of choice so it becomes a personal decision. I prefer MT6, but SRT6 only comes with automatic/slap stick.
4-SRT6 is faster, louder, more powerful, and a little harsher ride. Slightly different body and spoiler, rims, seats, badging. Gas mileage not as good, but I don't know an owner who bought one for economy. I have one of each and I love the manual and top-down of the roadster but I also love the power of the SRT6. I suppose if the SRT6 came with a stick, I would have brought one as a roadster back in 2005 and I would have just one XF today.