I bought a Subaru Forester 2007/07 in June 2010 from a Subaru Franchise. Within a few weeks it was back with an intermittent engine problem, which the franchise are unable to fix, despite help from Subaru UK. The franchise is offering to exchange the car, but the only replacement it can offer is slightly younger (2008/57) and slightly lower mileage (34k vs 52k). They are asking for a further cash payment of £1,500. I feel that they should do a direct exchange, in view of their acceptance of a problem with the original car. What are my rights in this, and how should I proceed?