I think you need a hi-vis vest for each passenger, they used to sell them in poundland. The breathalyser law has not been implemented and isn't likely to be because it was Sarkozy's mate who made them.
There are a few points about driving in France worth noting;
1.Speed limits are more strictly enforced than they used to be and the French are clamping down on non French drivers who used to get away with a lot. The normal extra urban speed limit of 90 kmh ends on entry to an 'urbanisation'. If there is a yellow diamond on a pole then the urban speed limit applies even if you can't see an urbanisation, assume this to be 50kmh unless otherwise stated. If you see a sign saying 'rappel' this is to remind you that there is a speed limit though it doesn't tell you what the limit is.
2. Giving way to the right.. on road juncions where the joining road has a white line at the join the main road has right of way if there isn't a line then you have to give way to traffic joining from the right. This rule also applies to roundabouts in towns and villages within the yellow diamonds.
About 50% of French don't understand this rule and so don't give way, proceed with caution.
3.The French have their own distinctive style of driving, they don't like using their indicators, they do like extreme tailgating(it's nothing personal). They like cutting corners especially at T junctions and they like to overtake at the last second, just when you think that they aren't going to.
They almost never use headlight signals except to warn of a police checkpoint/speed trap.
4.Road signs are confusing to the novice, a sign showing direction to a place does not mean go in that direction but go down the next road after that sign. Road signs are not placed ahead of junctions but at them so as soon as you see what might be a relevant sign ahead, slow down otherwise you will miss your turning. If in doubt follow 'toutes directions' until you get the destination you want signed.
At traffic lights drive up to the pole so that you can see the repeater light at eye level if you are at the front of the queue.
The motorways around Paris can get very busy but away from the large towns they are almost deserted and you can make very rapid progress, 130kph (80mph)is often the limit .
There are 'Aires' (rest areas)every 30 km, food & petrol stops less frequent.
Some motorway exits are quite a distance apart and you could lose an hour if you miss one so keep your satnav on to remind you.
A 'rocade' is a ring road where the 'toutes directions' sign is your friend.
Filling stations in the country are few and far between so keeep your tank above a third full.Driving in France is a lot easier than I have made it look, because the roads are so empty so give it a go.
I've been living in France for nearly 5 years so this is kosher info.