Targeting Brits straight off the boat is a nice little daily mail & sun fallacy, with certain exceptions with the types of Brits who often get the attention of police for same everywhere
Driving down to the south is possible but is a bit of a major trek, and at the moment you'd rely on good air conditioning for the journey to be survivable
On main roads decide on either paying tolls for ease of use or look for the alternative routes avoiding tolls, but on these you'll meet all the trucks etc. these are still better roads then ours
If you haven't already got a vest, triangle, first aid kit etc then buy something such as a halfords European travel kit. If you have a few of them then buy or borrow the remainder:
Gb sticker / magnet - unless you number plate has it covered
Headlamp converters
Warning triangle
First aid kit
Breathalyzer
Vest (for everyone in the car, and available - not buried in the boot)
Extinguisher & bulbs are not legal requirements but are recommended
For breathalyzers I understand the law had come into force, but fines are not yet implemented. So take your chances - spend a few pounds or take the risk
In Paris go down to pere la chaise and say hi to Jim morrisons grave, and there's a nice cafe around the corner