I prefer to do the car on Sat., too, for the same reason others have mentioned: I want a shiny car to cruise around in on Sunday
The ideal weekend for me, though, is a late Friday evening wash and into the garage; then I can toss on another layer of Z and do tire dressing, vacuuming, etc. first thing Sat, done by lunch. Then I have Saturday afternoon
and Sunday to cruise
Tort, staring sadly at the foot of snow that showed up yesterday