I'm pretty sure by now that most States have some time requirement for a buyer to re-title & register a vehicle.
Some may be rather lax in enforcing that date.
Some will be pretty aggressive, as it's revenue for them.
Title is proof of ownership, which would seem - but may not be - a requirement to be paid for an insurance claim.
Registering in your name would be a pretty logical follow-up from a DMV perspective.
For off-road use, it varies: some have "non-op", some have fees & tags for off-road...
Also:
Some if not all States have time limits for out-of-state plates if you've moved to a new State; I avoided that on a CA car I took with me when I lived in NJ for a couple years.
It was a toy, didn't see daily use, and never had an LEO stop me while driving it.
But on the PA vehicle I bought for a DD I went ahead with NJ title & "tags" (license plates) rather than risk a battle.