A 99 W210 would have the 5spd auto. That is a "filled for life" trans, however MB won't say what "life" means. I would say every 60k-80k, the dealer's only seem to charge $250. You have to use special MB fluid and a MB filter, also the fluid level must be checked when the fluid is at 80c. The dealer has a tool they stick in the dipstick tube to measure the fluid temp.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200