Not done that, I suppose it is the best place to start, it means a 200 mile round trip to my nearest main stealer though, it should be worth it to diagnose the fault. Kevin.
Your car shows the early symptoms of throttle body failure. Cleaning it may help in the short term. Search this forum for a long thread on the subject. Your car is OBDII compliant so any garage should have the equipment to read at least the generic OBDII codes which should give you a good indication of the problem and save you a long trip. You could also buy a cheap OBDDII code reader for the cost of taking it to a garage.