I don't know how strongly you feel about synthetics, since this is a hot topic on any auto forum, but you can do better. I personally don't believe in using synthetics, unless an application specifically states to use synthetic fluid or if it's for the differential.

PS fluid - For that price, the dealer better be selling synthetic fluid. I use Valvoline ps fluid for $2/qt. If you want synthetic, you may get something cheaper from Amsoil or Mobil.

Coolant - The last time I bought MB coolant two years ago, it was $11 from the dealer. Has it doubled in price since then? Zerex G 05 is the same thing and is available from my local auto supply store for $9.

Diff fluid - Use a 90W fluid, preferably synthetic. I believe MB specifies 85W-90, which I hear is widely available in Europe, but not very popular in the US. An 80W-90 should do fine. Use synthetic because any extra you pay in price over the few quarts of regular fluid is made up in the incremental gain in fuel economy, which adds up over time.

Transmission fluid - I haven't done enough research on what you can and cannot use. An eight quart charge is a lot of fluid to pay for the premium of using synthetic. The choice is yours.

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95 E320 Cabriolet, 169K