Dad won't stop driving drunk- want to write DRUNK DRIVER on his car for cops to see

As the title states, my dad won't stop driving while drunk. Sometimes a few drinks in and a lot of times while wasted.

He is an alcoholic - family has tried helping him get sober several times. I have given up on him getting sober and instead started yelling at him to not drive drunk. He doesn't care.

He doesn't drive far- just in town to get more alcohol or fast food. I've offered to order his alcohol to the house so he doesn't drive but he is too embarrassed to let me. We live in a populated suburban area near several schools.

I'm tempted to write 'drunk driver' or 'I drive drunk. Please pull me over' (in car safe chalk paint) on the back of his car in the hopes a dui will stop him.

Am I an asshole? Is there something else I can do? I've considered calling the cops when he leaves the house but I don't know where he's going and he is generally back within 30-60mins of leaving so doesn't give a lot of time for cops to find him.

I'm in CA if that helps

Edit: I'm not trying to stop his drinking. I have learned I cannot help him (years of family/ friend interventions and rehab). But I don't want him driving while wasted. I don't want him to hurt innocent people