Pretty much anything that can happen on the highway is going to come back to maintenance and operation (driver's/owner's responsibility).
Building faulty door latches and a dangerous electrical system that combine for char-broiled human, however, could be another story.
Just make sure you use a bill of sale that has a clause about requiring an inspection before use, and get it notarized at the time of sale.
"As-is, where-is, no warranty, no guarantee, and you have to sign this."
Like Tony's airplane, I had a highly customized car for sale and wondered about my liability if someone got stupid with it. It was safe and well built. But I wouldn't be able to prove that in court.
I ended up pulling the engine and transmission, and partially disassembling the rest. Everything went to the same buyer. But what they received was a non-running, non-road worthy vehicle that *they* had to put back together and for which they had to assume the liability. There was no way to reassemble the vehicle without inspecting every modification.
Man, admitting that and thinking about it, it sounds like something some crazy old man would do. I'm aging prematurely...
*Buyer wrecked the car about 4 months later. Talking on his cell phone while failing to negotiate a 25 mph corner at about 50 mph. Smacked a concrete divider.
(
Here. Before the light rail went in.)