When should I change the gearbox oil on my Mercedes C-Class?

I recently bought a three year old Mercedes-Benz C-Class CDI. I am very pleased with the car, but my local dealership tells me the automatic gearbox oil should be changed soon. This is an expensive job, and at only 31,000 miles seems a bit premature. What do you think?
Unfortunately now that torque converter autoboxes have at least six gears and often have eight, they do need frequent replacement of the ATF. This is standard routine maintenance.
Answered by Honest John on

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