That sounds great (ok not the light on the front which sounds like a hazard for pedestrians). I'd love to know if I was over the limit or not before getting in the car if I'd had a beer at lunch, or had several the night before.
Are the shaming aspects of this policy effective at preventing drunk driving?
All I see is the humiliation of a public branding. That's "effective" in the sense that "tough on crime" political demagogues can use it to win votes from the brutalized electorate. But shouldn't an engineering community like ours have higher aspirations?
For instance, there is an actual solution to drunk driving on the horizon: self-driving cars.
Therefore I would be quite happy to have something built in my car that checks I'm not drunk before I turn on the engine
I'd be even more happy in the very hypothetical case where I'm willing to drive drunk (say a volcano had just erupted) and all it would do is light up a warning light
(that said I know when I've had too much to drink -- like now at 2300 after a succefull 12 hour day, and wouldn't drive, it's when I'm in that 'I don't know if I'm impared state', that's where the breathalyser comes in helpful, so there's no need in my case to do anything with the results other than present them to me)
If that's truly the case, it's trivial to get a voluntary interlock ignition device installed on your car. You'd most likely save on the cost since there is no government mandated reporting.
That said, I'd recommend not driving at all if you know in advance that you are going to be drinking. At least in metropolitan areas, there are far too many mostly affordable and convenient options IMO to risk it. Even a couple of drinks for a 180+lb person is going to cause impairment.