Just to let you guys know, I spotted a new M5 driving down the 210 last week in pasadena. It was disquised so as not to bring attention to itself, but they couldn't fool me.
It was a tannish silver color with the new front and rear bumpers painted primer black and no badging whatsoever, not even a BMW badge. It also had the side "gills" covered with tape.
So be on the lookout in the southland and have a camera ready. I wish I did!

ghead