Sir – On Monday night, I arrived in the short-stay car park at 8.12pm at Oxford rail station. I duly got a ticket from the parking machine, which gives familial taxi drivers 20 minutes grace before slapping on a £3.50 charge.

The ticket announced a time-warp difference of six minutes, effectively giving me 14 minutes before I had to pay, which seemed a very convenient mistake of the machine for APCOA.

Is this a sneaky way of catching drivers out even more?

R Lewis (Ms), Kidlington