Problems obtaining a remedy for a faulty second hand car!

[johellicar]

A friend of mine purchased a second-hand R-reg Renault Scenic in July from a registered car dealer. Within the first month of purchase, problems arose with the starter motor, which the car dealer was happy to repair. The same problem occurred a few weeks later and again, the dealer attempted to fix the problem. The same problem then arose a few weeks after the last lot of repairs, along with problems with the vehicle's exhaust and the car-dealer would not accept the vehicle back for repairs since the faults had occurred outside the three-month warranty period that he'd granted at the time of sale. My friend spent £220 getting the exhaust repaired by a third- party garage. A week after the exhaust was repaired, problems arose with the clutch and the initial problem with the starter motor is still apparent. My friend has not driven the car for the last six weeks since she no longer feels it is safe to drive. She has contacted the car dealer, but he refuses to remedy any of the faults to the car, since the three-month warranty period has expired and he has already spent £500 attempting to repair the starter motor. She asked me if I would send a letter to the dealer, since I have some legal knowledge, stating his position as a dealer and his responsibilities under the Sale of Goods Act 1979 (as amended). He still refuses to provide a remedy and insists that he is not legally obliged to. My friend wishes to pursue the matter in the County Court, but the dealer's reluctance to provide a rememdy is making me wonder if he's actually right, and does not have any legal responsibility to repair the vehicle. Any advice on the above matter would be very gratefully received!!
Thanks
Jo