The auto box has been fine until a recent 500 mile motorway day-trip after which it has become somewhat erratic when sometimes it shifts from 1st to 2nd with a delayed and a slight high rev motion . This only happens when it has been driven a while and at random - not all the time! The tranny oil is clean and at the correct level, although I was thinking of changing the oil & filter to see if it cures the problem but the weather has been rather wet and cold! The car has done 190K and is otherwise in excellent mech/elec condition. Any ideas what could be causing the problematic behaviour of the tranny?