Stuck throttles used to be quite a common problem in the pre-ECU days.

I've had two cars that had a stuck throttle in the past, both where the accelerator cable connects to the throttle body on the top of the engine. In both cases, lubing it up solved the problem and it never reoccurred. It is a bit of a shocking thing to happen, but with a manual it's instinctive to just jam the clutch down.

What worries me about modern cars, in particular electrics, is the lack of any kind of kill-switch. Motorbikes have them, cars used to just have an ignition switch, but now everything from the ignition to the accelerator pedals is electric. Wouldn't it be a good idea to have a switch that kills the car if all else fails?