Probably.
function scooterVehicle::onAdd(%this,%obj)
{
%obj.setWheelTire(0, scootertire);
%obj.setWheelTire(1, scootertire);
%obj.setWheelSpring(0, scooterSpring);
%obj.setWheelSpring(1, scooterSpring);
%obj.setWheelSteering(0,1);
%obj.setWheelPowered(0,true);
%obj.setWheelPowered(1,true);
}
Presumably you could set the wheel types in each slot to different ones.