My RAH always drank and drove, for several years now ever since his relapse. Last year, several times, I called the police when he drank and drove, and they would do absolutely nothing!!!!! Once, they brought him home after he hit a curb, drunk as a skunk. No arrests, nothing! Just "he's your problem now, don't let him out for the rest of the nite" to my son!
Fast forward to this year. We split up, he proceeds to get 3 dwi's in one week. Needless to say, he got jail time. He's out now, on probation for 3 years, working a program, in treatment, and so far so good. I take it one day at a time.
In any event, right now your A is getting a false sense of security. To tell an A, "just don't drink and drive" is like telling storm clouds not to rain! Trust me, it will happen when it's supposed to happen. Just let it go, it's out of your control.