I bought a lovely BMW 530d on an 05 plate from a dealer. When I went to pick it up everything was fine. When I got out of the village and got my speed over 40mph the tyre warning light came on. I returned to the dealer, who said there was nothing he could do as it was Saturday afternoon. His mechanic confirmed that he had to top the tyre up the day before during the PDI. They advised they could over pressurise the tyre and I could take it easy on my 60-mile journey back to Bristol. When I took the tyre to the local specialist he found a split pin/staple in the tyre immediately, and as they are runflats he could not repair it. So I spent £180 on a new tyre. The dealer is ignoring my requests for a full refund. Whats your advice?