When I bought my Magnum SRT8 in 2006, it included "The SRT Experience", which was a day of fun at a selected race course. I went to one in SoCal (Auto Club? Can't remember.). We got to drive all of the different SRTs (including the Crossfire!). The Grand Cherokee was the most impressive... nothing I'd ever driven launched like that thing, and it was no slouch around corners, either.
At one point, they had us drive Vipers (with a coach) around an Auto-X course. He kept telling me to drive it harder, but I knew that these things were unpredictable. After all of us had a chance, one of the coaches said he'd show us how it's done. Third turn, the thing did a quick 180, and he locked up the brakes, stopping with the ass-end maybe two inches from a concrete barrier.
Oh, and they sound like a UPS truck, too.