I agree with you, I think this DUI provision is fucking ridiculous. However I can't see how they could possibly enforce it, many are echoing this same sentiment. If you're too stoned you've actually given a LEO probable cause, you shouldn't be driving anyway. If case you're unfamiliar how probable cause works in a traffic stop, in order to be stopped solely for that you must build up "points". Touching the center line is a point, swerving is a point, riding without headlights is 3 points. Once you reach a certain limit, you get pulled over. I really hope you're not so stoned, you're going to get pulled over. Let's say hell freezes over, and you get charged with a DUI for 13ng/L... fight it in court. I have heavy doubts an MMJ patient is actually going to get convicted by a jury, that's irrational, you'd always have THC in your blood.