How important is it to change the tranny filter, and where is it on my 95 E320 (wagon)? Also, where is power steering filter? Finally, and this may seem dumb, but I don't have a cap & rotor, right? It's electronic? I changed the plugs under the engine cover on top, and saw electronic boxes.

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2002 Mercedes-Benz E320 4Matic
1995 Mercedes-Benz E320 Wagon
2005 Land Rover LR3 V8 SE
1999 Audi A8 4.2L quattro