The RAC misdiagnosed my car having been incorrectly fuelled, they instead gave me a new battery as if flooded mine trying to start it, then it went again an hour later and they misdiagnosed it again saying there was air in the primer pump and got it going again. My garage knew straight away, as soon as they opened the bonnet and attended to the pump due to the smell of petrol. The car is diesel. They said had the RAC mechanic asked the right questions they’d have worked it out easily. I complained as I have a new (expensive!) battery I didn’t actually need but the RAC missed my complaint completely. I have now cancelled my membership as I feel completely ripped of and have no faith if I break down again a mechanic will be any good whatever the problem is- it took them 8 weeks to answer the complaint by the way.