John Rowland wrote
[...]
As you are expected to pay for the petrol that you
use from the car I don't see how this comparison is valid.

Okay. The "5 pounds for 75 miles" bit fooled me. If they expect you
to pay
for petrol, I don't see why they charge you extra for more than 75
miles per
day.

Pay for mileage or excess mileage has been a option on car rental since
the year dot (except on very small islands where petrol may be included
too). I take it that the higher the mileage the lower the price when
they sell on their cars.

--
Mike D