Last week I went to have the Transmission Fluid changed on my 40k car and was told that it is a sealed system from the factory and is good for the life of the transmission .... riiight! Must be, becaue I cannot find any filler tube, etc. Then I asked about flushing the coolant and was given a similar story. My question is, if I decide to flush the coolant on my own, can I use the long life antifreeze (Prestone, etc.) or do I have to use the stealer recomended $40 gallon stuff? Also, why is it available, if it is good for the life of the car?