My son just bought a slightly used 07 Toyota Tundra. I was suprized to learn that it had a "sealed transmission" and did not require a fluid change for life,(or 100,000 miles-depending on who you belive.) This was a new one on me and some of the web sites i've looked feature guys who have gone to alot of trouble to change out the fluid as it does not seem to be made to do this easily. Is this really neccessary? What say the Glock Talk Brain Trust?