Also local trading standards, they are often pretty helpful. They will sometimes put a test car in to see if the garage are adding unnecessary work to bump up the bill We had a problem after Renault Birmingham told us we needed a new engine and automatic gearbox on a Velsatis £20,000 approx on a vehicle that cost £5,000. A second garage diagnosed a simple problem related to the air con fixed for under £100. Just because my then partner looked like a sweet grey haired old lady they tried it on. Renault head office backed their own mechanics... Until trading standards sent in a car ( appropriately selected driver apparently)