Thanks Banks for the FindPath - yep, as I just put down the vehicle on the field I'd just do a quick A->B but that way is far better.
Ataros - Excellent script from narvy, could have done with that yesterday
It seems to do quite a lot, such as make sure the vehicles don't bump into the target aircraft (my ambulance was quite destructive) and dynamically spawn the vehicles in the airport dependent on the activity/closeness.
I love that on landing it can decide whether to put out a fire, re-arm you or go capture you as an enemy. Good stuff - thanks.