Re: limited top speed
The non-SRT6 is electronically limited to 150 mph and the SRT6 to 158 mph. I've had my roadster to 140 and the SRT6 to 150 and climbing (when I ran out of road). Both are stock. You can see from the answers, that with some performance parts and a tune the SRT6 can exceed 170 mph. I hope you find an SRT6 and do the mods -- you'll be the only one who can safely (or at least legally) test and tell about it's true top speed.