My grandfathers. He let me drive it once with him in it, I drove the speed limit. I also attempted to take it out once while he was out of town. I got it sideways in the driveway and decided that I shouldn't take it out on a public road, not because I feared I was going to kill myself. But I feared my grandfather would kill me if anything happened to that car.
If I wrecked it and lived I would have to live knowing I wrecked my grandfathers dream car that he wanted when he was a kid and got when he was older and well accomplished, I couldn't live with that burden.
One thing I do have is trust though, I have keys to every garage/shop of his and he told me where the keys for the cars are.. in case anything were to happen to him.