Simple: Put a breathalyzer on every car, and it won’t start if you blow past a certain percentage.
Also, since you are so obsessed with this concept to deflect the gun issue how about this: When we all have self-driving cars and drunk driving has been eradicated, THEN can we ban guns? Or are you just going to shift to another false equivalence? Because if its the latter, you better get it lined up. Google cars aren’t that far away.