1993 BMW 325i Shakes

This is my first beamer. It has High Miles 210k. I I bought it in Salt lake and drove it home to Boise, which is about 350 miles away. When I turned it on the next day it was shaking in park. When I put it in neutral the shaking whent down a little and in drive it gets worse. Could it be that it needs an idle adjustment? If so, where is the adjustment knob?
Sam

Does the shaking stop when you give it some gas?

i'm guessing a misfiring cylinder. check that all your spark plugs are firing (refer to basic service manual). actually, just pull the plugs and make sure they are all clean and not mishapen first.