It's your car, do whatever you want with it. If you want to keep it stock, fine, if not mod it. I have a friend that has a 1957 olds 2-door post with the 372 j-2 engine. It came with an auto, very rare. He chopped it, souped up the engine, put a 4-speed in it and it's one bad ass hot rod. The people at the olds club almost had a heart attack when they saw it. It's beautiful now and just as he wants it, because it's his car. Do to your car what makes you happy, if it's not fast enough for you and you can make it faster and are willing to sacrifice some reliability go for it, if not don't condem others because they chose a different method of car ownership. This isn't a collectivist society of car owners, no one can tell you what you can or can't do to your car (unless it's like putting a quad 50 anti aircraft turret on the top) Good luck to everyone with whatever they decide to do.
-Nate

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'82 240D, 4-speed, 617 turbo engine