Now not only do you have to have your own twin pack of alcohol breathalysers with you, but it is now illegal to have the Speed Camera detection option active in your own SatNav. See this Telegraph article for more info about this and other motoring relating issues across the European countries.
Make sure the alcohol breathalyser test kit is an approved version by the French Authorities – as not everyone available in UK. You can find them at AlcoSense, Amazon and a number of other outlet if you search the Internet. These will be required to be carried by 1st July.
Make sure you know how to turn off the ‘Speed Camera’ detection in your SatNav before you get into France, I found two places in my SatNav that I had to un-tick’ to make sure that it was completely disabled. Check the documentation now as it better than getting as fine when in France.
Bonne journee!
Beasley's Place 
Hi – You've put together a great post here. Driving to France for a family holiday or a short break can be a fantastic way to save money, especially given the range of offers available for ferry/Euro tunnel crossings. It's important to brush-up on driving etiquette aboard before traveling, and to take French toll road charges in to consideration when setting off on long journeys. The Sanef toll road tag is a handy way for British drivers to save time at the toll booths as it works on an automated payment system. Just one less thing to worry about when traveling abroad!
Best wishes, Alex.
LikeLike