I find I get better service online than in person. You can email or talk to someone who knows what they are doing (like Phil), instead of getting a blank stare from the teenager behind the counter. You can go to the dealer instead, but the service is not certain to be any good, and you will pay dearly.
Ironically, I have found that the stock on hand at the dealer is not that great, so it often takes LONGER than shipping to get a part in hand, plus you have to drive there twice.

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1986 300E 5-Speed 240k mi.