I rode a motorcycle @100+ MPH for nearly an hour on a public highway, and slept in a parking space at a rest stop next to said motorcycle with cars and trucks passing left and right- Sleeping like a rock... It was amazing, but I would not do it again unless I was magically transported back into the body of a twenty-something. I think now that I'm advancing into the later part of my forties, sleeping in a parking-lot on asphalt would fuck up my hips and put all of my limbs to sleep- That happens to be a really, really uncomfortable "wake up" just as an FYI for all of you youngsters.