My 04 Yaris T3D-4D has twice exhibited a problem that I am at a loss to diagnose and would be grateful for your comments. When driving up a slight incline the engine revs to a high speed for no apparent reason, and sounds as though it will take off for the moon. Fortunately I have been able to stop quite quickly. Several months have lapsed between these two occurrences. On switching off and waiting a while the problem seems to be resolved. However, the thought that this might happen at a critical time is a worry. These symptoms would seem to indicate that the clutch is slipping. I have read in the motoring press that some cars are fitted with dual mass flywheels, which can cause problems. Can you tell me if the Yaris has this type of flywheel, and might this be a factor? I would be most grateful to have any suggestions and thank you