Drive 75 in an 80 zone.  And, somehow I always think that if I get my front bumper within 18 inches of your ass, you will speed up out of fear.  Your hands will get clammy as you look in your rear view mirror and see the grill of my Jeep turning into an angry, evil grin just like in Christine.  Classic movie.

Just because you planned a buffer into your day doesn't mean the rest of us did.  Seriously.