Here is a quick, simple, and easy way to get rid of it. It takes all of 2 minutes (if you are slow). It is not 99% perfect, but since 99% of digital camera images are resized smaller for the web (where the license plate matters), any imperfection left would not be noticeable (unless the lighting was reeeeeeeally bad). Enjoy!
http://www.e30tuner.com/bmw/articles_lprmv.phpI also put it in the big How-To thread.