Thanks guys!
Can I ask what rules you plan to use for the gaming?
Sure, I'm thinking of using the movement from Car Wars, and cobbling something together for the combat as I'm having very few vehicle mounted weapons. I'll be digging out my old Car Wars rules and having a look at the petrol rules, and other car games for a clue.
As Scurv said on his Mad Max thread, Car Wars are good solid, and much adored, rules - but with a great number of cars it can get too much.
I'm also considering an element of bingo, namely for each turn a player gets a random chit, "Oh", "what", "a", "lovely", and "day" which once a full set is played an heroic move can be done, something like succeed in a roll without having to roll, etc...