The Davis sensor is pretty wild, It isn't as expensive as I thought but still too rich for my blood for something to play around with. In a car that could fully utilize its functions its pretty fair priced all things considered.

https://moretraction.com/vps/

Something more simple that would still require an ECU would be wheel speed sensors on the front and rear. If the front sensor doesn't line up with the rear sensor in X amount of time it pulls timing.