How about
"go ahead and honk
It's still my gas
" (bumper sticker)
or
"Hop in and gain
it's the slow lane train" (Slogan)
And people like me could be in the front, like the giant wind blocking smoky gassy train engine. Smaller cars can brake to a stop faster than larger vehicles, (if the brakes are properly maintained). If I brake, you will be aware because you are ecodriving (unless your watching your scanguageII) and brake, you will slow down faster, and won't hit my vehicle.