I recently did what appears to be what an ever increasing number of diesel fuelled cars owners are doing in that I filled my diesel Focus with petrol. The total cost of repairs, I was very luckily covered by my insurers, was £1,750 which was relatively cheap considering the £3,000 for a local BMW owner who made the same error and an ever increasing number of insurers will not cover for this mistake. At my local Shell garage I was the third that week and at my Ford garage I was the second that day. These errors are a lot more frequent than we are informed about and I have never seen any advert for the devices that are now available to prevent this incorrect fuelling from being performed. I bought one from the internet for £50, which I fitted in seconds. Could I suggest a mention in your column to remind people that it is easily done and very easily prevented. I must say that everyone who I mention my problem to has either done it themselves or knows someone who has made the mistake. On the fuelling nozzle at the Shell garage there was no indication of either petrol or diesel on the nozzle head, only the colour of the plastic surround, as to which fuel was being dispensed which could have been the life saver for me. I have been called an idiot for doing it but believe me it was very easily done.