Drink driving in France - the dilemma!

This amusing new law is about to come into force in France. My nieces have been lamenting it on Facebook for weeks. I'm sure it was brought in with the best of intentions but one summed up the stupidity of the idea: Roughly translated she wrote 'I have to have an unused breathalyser test in my car or I am not allowed to drive it. So I leave my friend's house after a glass of wine. If I use the breathalyser to see if I am allowed to drive, then I have used it so I am not allowed to drive! If I don't use it, I might be over the limit so not allowed to drive! Best solution is probably just to stay at my friend's house and get drunk!'