The car over revs between gear changes - the problem gets worse the harder you accelerate. Sometimes during hard acceleration it completely loses the plot and gets stuck in a low gear. Usually, the only way to regain control of the gears is to pull over and restart. Main dealer has already changed gearbox wiring. They report oil contamination of gearbox control unit via engine harness and propose changing both (about £2,500!). As their strategy seems to be to randomly change service modules (at my expense!) until they accidentally get it right, I'm keen to see if anyone has any less wooly ideas?