Lexus ES 350 Changing Transmission Fluid

I would change the fluid.

I am certainly no expert, BUT ... I called the Lexus dealer re my 2007 ES350. They said the transmission is a closed system is not designed for changing the transmission fluid. With proper use of the vehicle, they said, it should never require changing. But that assumes that transmission fluid never breaks down ????? I am confused. Any thoughts?

Don't believe Lexus Customer service. They are not Xmission design engineer. I am M.E and I have 2016 Lexus ES350. Renember: Nothing for ever. 11 year and 98,000 miles wo xmission service is extreme. You must change xmission fluid NOW, drive 2000-3000 miles after change fluid, don't drive for 2 -3 days then change xmission fluid and filter.

I have called a few Toyota and Lexus service centres. None of them is willing to perform this service. I have a 2016 ES 350. I am concerned as I don't believe this fluid will last the mileage I want to put on this car, even if driven "sensibly".