i recently read a thread on undertaking on the 5ive-0 forum ( moderated by police ) They dont have a problem with undertaking dawdling middle lane muppets on the motorway AS LONG AS YOU DONT CHANGE LANES TO DO IT. If you swerve from lane to lane to undertake and then swerve back in front of the undertakee they will pull you, if you just cruise past keeping up with traffic or in an empty lane then they would be unlikely to pull you according to them as you arent at fault the dawdling muppet is. Its a great forum, check it out

www.5ive-0.org