if it was me i would go with a socketed standard 30a car relay,simple cheap foolproof and easy to replace.
That was what I was thinking as well. Also because mosfets tend to fail shorted. What happens if the mosfet blew up somehow or because of a design fault (high possibility, to be honest). Throttle body is stuck, maybe wide open and I might have a problem (yes). Relays often tend to fail open so that means, clutch is disengaged. Obviously we still have the transmission clutch if its a manual (in my case yes).
Even expensive cars car have cc issues. So, I am taking all measurements to make it as safe as possible hard wire off switch interrupt that checks horn & brake pedal switch. Looking at the flow cart of Honda, I might be better off adding the gps speedometer to it and when set if speed is off by x amount of % and tilt sensor is completely horizontal. Disengage clutch, spin servo to back pos for few seconds just in case it was "stuck". Can't see a thing that could go wrong.. I mean yeah the code, there can be a bug or fault. But first need to make the clutch safety test property and build the first prototype.
Only con I can see with relay is that it can't switch as fast compared to a mosfet. This may be a issue, I still need to order lots of parts for the prototype because my selfs are empty. But having issues with delivery from AliExpress (taking really long). Even from before Corona virus. I might need to order elsewhere but the price would go up by 80% >.> Breakout boards on Ali 0.56 euro shipped. Here 6 freaking euro!
When the concept works, I order premium parts no knock off shit.
Some friend was telling me a story a while ago that his boyfriend had a fancy car but was also old. When he was driving on the highway the gas throttle was stuck. He panicked and was stamping on the gas paddle in the hope ot would free up, hmm why not press the clutch. Assuming it was a manual car. Of it was a automatic, why not just turn off the engine.. It is designed to be turned off in case of a emergency..