I use those little servos and have hundreds of hours with them. They work well, but on something like a throttle control, there needs to be some kind of glitch detection implemented that will shut it off if something goes wrong. Of course the brakes will overcome the throttle, but... at least n my case, I'd be hesitant to trust the servo at all. They wear out and the reading within the servo (an internal potentiometer tells it where it's at in degrees of travel) will become erratic and the motor will act up. This likely would be a problem if this "acting up" gives the rack a full throttle motion at the wrong time.

My thinking is that some sort of feedback that confirms ok travel allows the servo system to continue. Then if this feedback reports travel that isn't commanded, power to the servo is killed. This all is in hopes that killing the servo power still allows the throttle spring to pull the rack back to zero throttle. I'd think MB's cruise system fails to an inactive uninterrupting state.

All of this contains risk like anything in a vehicle system. But there's much more risk for someone doing this for the first time. When MB designs such a system, they have a history of design improvements and failure assessments which in turn form standards. I don't know that I'd mess with it personally as someone who doesn't have this history. The idea is fun of course.

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