What happens
Found it flat in High Wycombe? Leave it where it is.
A flat on a High Wycombe hill is more tempting to move than one on level ground. The car is on a slope in Downley or Sands, the nearest tyre bay is down in the valley, and it seems only a short roll. That roll does the damage: the rim pinches the sidewall against the road and a repairable nail becomes a ruined tyre. Commuters back from the train meet the same temptation in the station car park, if permitted, after dark.
Leave the car where it sits, put the handbrake on firmly and turn the wheels into the kerb if it is on a gradient. Message a photo of the flat tyre and its size. Beside the car on the Downley slope the tyre is unseated, the cause found and you are told which it is: a tread puncture patched to BS AU 159, a faulty valve, or a replacement from the van. Prices for both outcomes are given on the call.
On run-flat tyres? They behave differently once deflated, so check the handbook's limits and read our page on run-flat tyres; we fit replacement run-flat tyres at the car in High Wycombe as well.
Other services from the same Brent Cross team: broken tyre replacement in High Wycombe and wheel balancing.