I'm 6'3" and 195. In my 3rd viper, I've done 4-11 hrs at a time and been as comfortable as any other average car. I avg 23-25 mpg on long highway cruises. Biggest test was just this past VOI. After the events I drove down to SC to visit some teams I have there, then drove back to Maryland, 11 hrs, pouring rain and fog, through the mountains. Car handled totally fine thru the bad weather, only time it's seen rain, and even creeping along at a safe pace I was as comfy as you can be for sitting that long. This viper interior being uncomfortable is an urban legend IMO. for the wife, she's good for an hr, for longer she's ok if I have the top up. It's not the comfort but the noise that gets to her, I have an Aero exhaust and with the side pipes it's just about 36" from your ear. On those 4+ hr drives I go top up myself, at VOI we did a never ending 5 hr cruise and kept the top down, end of the day I was fine comfort wise, but my ears felt like I got home from a concert. LoL
Dave.