You need to give us some more information before someone can help you.
BMW makes 2 screens for the Roadster. One is a small sport screen or "fly screen." The taller one is called a touring screen. The mounts are different. Check RealOEM Parts to verify the one you have. If you can post some good photos of your screen on Photobucket, and paste the link in your post, then someone can probably ID it for you. Also, you may use the SEARCH tab to pull up related threads & posts about what you need. Oh, and Welcome to the Forum.