Yes, if you're short on electrons to make it home, drafting can make a substantial difference. There are safety concerns of course, not to mention getting something kicked up that messes up your windshield. I don't do it very often, but it's good to know as an option when truly needed to avoid being stuck w/ a dead battery. As for them minding it, unless they have a rear camera, they probably can't see you if you get close enough .............. "If you can't see my mirrors, I can't see you."