I have recently bought a new Mercedes C-Class Estate after a two-hour test drive in which I drove the car for three 20 minute sessions. The day after delivery I did two 90 minute journeys and was left in pain all day. Over the following 10 days I was left in pain for most of the day after a 15 minute drive to work. I can drive other cars with no problems and have swapped cars with my wife to stop further unnecessary pain. The dealership has been helpful - I've tried a GLC but have the same issue with the seats. Over the last year, I have driven a number of other cars with no problems, as well as flights and numerous chairs. Do I have any rights in consumer law? From my point of view the vehicle has a fault that can't be rectified by the dealership or manufacturer.