4 month old naps in her car seat?

I was just wondering if anyone else has a baby who will EASILY fall asleep in their car seat, but will fight naps everywhere else? I've tried her swing, her crib, her Pack-N-Play, and her bouncie- But she'll fight her naps like crazy. In the car seat, she just relaxes and goes to sleep. I don't even have to rock it. She still only naps for an hour or so (even when she naps on/with me, she'll only sleep an hour max. Never really been a napper, but she has been sleeping thru the night since 2 months w/ no cereal. However now she IS on cereal), but her Dr says that's fine because of how curious and observant she is. Anyways- Does anyone else have a baby who falls asleep in the car seat when it's not even IN the car? Lol.