As mentioned previously, a heat gun or hair dryer will help soften the adhesive or double sided tape used to attach badges, and WD40 and Goof Off work well for removing small amounts of adhesive. They don't work well for removing large hunks of tape, however.

I recently removed the side badges on my 940 and was left with big hunks of tape that I couldn't grab well enough to peel off and that were too big to rub off. I talked to a body shop guy and he suggested that I use a razor blade! After getting over my initial trepidation and gingerly approaching the task, I found it worked it worked really well. By laying a single edged razor blade against the car body and using a sawing motion, I was able to slice away the tape and leave just the faintest residue of adhesive which I removed using Goof Off.

BTW, Brake Kleen will absolutely kill the finish on your paint. I'd stay away from it.

Peter