Manners please

Oh... and if it's very obvious that I'm faster than you (i.e. I overtook you about 5 minutes ago, and the only reason you caught up with me is because I stopped at a red light), then do not pull out in front of me at said red light, forcing me to have to overtake you again as soon as the light turns green.

+1 - That drives me insane. Especially when it's "I've overtaken you at the last 5 lights"