That depends on your fuel mileage.
Trivially little if you got on your bike!
Depends how the driver drove the car.
From Cardiff to Glasgow is some 400 miles and would cost about £75 in petrol.
It would cost (2.4) times (the cost of one gallon petrol). Also, add cost of tolls, food, etc.
Not very much. Between $13.00-14.00.
Depends on how many miles per gallon your vehicle can travel
That depends how many miles per gallon you travel.