The girlfriend's don't add anything to your percentage though - best off doing those RC missions if you wanna finish it completely!

The thing with the aeroplane mission is to know what route to take (take out the ones closest to you first and then work your way across town to the last 2) and remember that the fuel gauge is actually a timer - so it doesn't matter whether you're conservative with the accelerator or not, the fuel goes down at the same rate.

I also found with this level that you had to be lucky where the game places the last 2 delivery drivers, because if they're in a position far away from Zero's HQ you'll end up with not enough fuel to get back there

IMO the best thing to do is to buy the Brady Game's strategy guide - helped me no end in completing the game

Cheers,

Andy