Pablo's mum owns a hotel in Chamonix and a restaurant in La Thuile in Italy, so we are there all the time!
Do be careful with regards to being timed on the toll booths, we have seen it many times.
Be warned if they catch you on the motorway you will be escorted off the road to the next village to withdraw cash! They will not let you go even if you plead that you have no money they will take you to a cash point.
Speed cameras are front facing - warn you a little before and blind you when you flash!
if you leave the country without paying a speeding fine, they will not allow you back in before you have paid! so there is no getting away with it!
Make sure you have your driving license, we once parked and got a parking fine from a police officer, we didn't have our driving license on us so they fined us!
Be extra cautious doing the mont blanc tunnel run, watch your speed! there are an awful a lot of mudslides there too, we came home last week and the tunnel had been closed for ages!