My ins(farm beaure) has a policy that "anything" I buy has ins for 72 hours,this covers a fri purchase to cover until Monday.
They even put this in writting for my bus purchase,and I just used the tag the dealer gave me and went with it,50 miles no issues.
If I would of got pulled over (wrong wt tag) I had my ins,a bill of sale/title and I would be nice and play dumb
I also left the local school district on it and just happened to drive it home on a Friday afternoon which means the cops never even looked at me with all the other buses on the road