Driving etiquette-wise, and local rules, regulations, blah blah, f*@k yeh! Signal before changing lane.
When I'm in my 650, go ahead, cut me off, I'll be ladylike and let it go..
If I'm in the M5 or M3, you cross my path, I'm in a pissy mood & had a sh*tty day, especially if you are a big Ford F150, BRING-IT-ON!!!!