 And only on the 10th time did he take offense to it. Blazing KC. A car nap is about as satisfying as skim milk. Like I said, you probably don't achieve REM sleep in a car nap. But I don't know. I bet you there's somebody who's a part of Car Nap Nation would say, no, yes, you do. Yes, you do. Best sleep I get is in my car.