Black paint for the windows of your love nest so your chossen lover does not know what time it is this will add in the lack of details they can give police and buy you time
The flics will still test you if they stop, no one is sure what the procedure is, the general consensus is that you use it before you start driving if you have had a drink, if you don't use it and get caught then presumably the flics cart you off. The alcohol limit is very low in france, one beer could send you over the limit.
Oh dear, when I was driving around Paris after a gig our local friend asked how much I had to drink. When I replied that I had three he seemed kinda worried about me being over the limit....
wow thats limp wristed