The 1980s Ferrari 308 series did not have a glove compartment, all documents or items would be stored in a pocket on the back of the passenger side seat.
Whether a driver remembers what happened during a crash or not would not have anything to do with an insurance company covering the accident.
A Ferrari that crashed in the way it did would not be simply fixed by some repairs at the local body shop.
A car that has gone off the road and crashed downhill on rocks is unlikely to have the driver's seat remain in exactly the same position as before the accident.
When Magnum figures out that someone else drove the Ferrari, then placed him in it before pushing it off a cliff, he states that it must have been a pretty big guy Dave. Magnum states that he had to pull the seat forward when he got back in the car, implying that someone bigger than him was driving. In reality, the actor playing Dave is an inch shorter than Tom Selleck.