My husband thinks that there's no better preparation for a nap than crying. I think he might actually be onto something.
Since we've been sitting in the non-moving car, Chuckles has been screaming and crying right before he falls asleep (usually within 10 minutes). Previously, there was no screaming, no crying, but it took about 20 minutes of driving. The nap length is the same. On the days when I have the mental capacity to listen to the screaming, then I don't drive (I sit in the car reading while it's not moving while he falls asleep, so I hear the crying...perhaps I should try getting out of the car and sitting in a lawn chair and work on my tan). Anyway, maybe teh screaming and crying releases tension or something allowing sleep to come sooner. Or maybe the garage is a whole lot more boring than the neighborhood where there are CARS and TRUCKS and buses and GARBAGE trucks and people with LAWNMOWERS cutting the GRASS.