1) Fill up with fuel at Dover (or where ever you cross) - it is cheaper than in France.
2) Use super unleaded in France, standard unleaded is 10% ethonol and may damage seals etc on an older car, it should be okay on an F but why take the risk?
3) Directline seem to offer the best european breakdown cover, I've only had occation to use my breakdown cover once, that was with the RAC and their service was very poor, durring and after the inccident which was in the newest vehicle I've every taken overseas.
4) Take a good atlas with you, plan to use some of the route nationals rather than just the motorway, it is more interesting as well as avoiding tolls.
5) Do not travel on the 1st, 3rd or last weekend of August, most of France is on the motorway - 1 year we did and a journey that I've done in 16 hours door to door from Bilbao to Sussex took 32 hours!
6) Listen to the autoroute traffic radio (107.7 IIRC) the info is very good.
7) Get and use a credit card that offers "no handling fees", Halifax and Sandanter do them, so do others. Credit cars are safer than debit cards, just rember to clear it when you get home.
Home to black Alfa Romeo 159 3.2 V6 Q4 ,green MGF VVC and red MG Maestro T16.
MG - the friendly marque.