If I have trouble with a Prius on the highway, my
favorite thing to do is to get in front of them, and constantly slow them down and let them speed back up. I do it when trucks cruise in the left lane doing 60 too. The one thing hybrid owners and truck drivers care about is gas mileage. If youre gonna sit in the left lane like a putz, im gonna kill your gas mileage until you get the point.
Hop in front of em, bring em down to 45, then speed back up to 55. When they catch up, bring em back down to 45. And repeat.