Tyre pressure warning light came on dash on Friday. Closer inspection revealed the rear passenger tyre had fell to 20psi as it had a piece of metal in it about an inch from the otside shoulder. Can it be repaired so close to the edge or would that be risky? Just been to Costco who quoted me

Might be repairable, but anything on the shoulder has to be a bit dodgy. Usually repairs can only be done for nail / screw puncture wounds, and slices/slashes in the wheel might be more difficult.

A while back I had a puncture done at Quikfit and the manager had a gauge which measured in from the shoulder. I think he said it had to be 12mm inboard, assuming it was repairable in other respects.

Replaced the tyre via tyre-shopper.co.uk who directed me to a tyre place in Ashton. They fitted a new Continental in about 15 minutes. Paid the balance on the net and turned up with a reference number. If I hadn't done the deal on the net it would of cost £170.