Bob was one of the most clearheaded problem solvers out there, regardless of domain. When I was designing high-voltage CRT drivers, his books and columns were invaluable. When I moved on to digital, then FPGA system architecture, then management, again his thinking was almost always mappable in some way to the problems at hand.
When he wrote a self-published book on driving, _How to Drive Into Accidents and How Not To_, I bought and read that too (472 pages on driving).
For those that say Bob was not serious about seatbelts because he apparently was not wearing one, he talked in detail about how that Beetle had rotted belts, how he had purchased nylon webbing to repair them, and his difficulties in finding a good, robust way to sew them. He made the point that a seatbelt "holds you down firmly and helps you AVOID having an accident." [Bob's emphasis]
The man was not perfect, and I'm sure his actions did not always match his intent (did you ever see pictures of his desk? or the back seat of the Beetle?), but we've lost a great thinker, and he will be greatly missed.