I worked out a while ago that it must take about
12 ltrs of fuel @ about £1.60/ltr = £19.20
Tunnel 3.5 to 5tl each way = £ 3.00
Parking 5 to 8 tl = £ 2.00
Total = £24.20
That is before the cost of the vehicle, wear & tear, tyres etc and labour which as a minimum is 2 hours.
How can they possibly make any money at £25?