The act of a fat person driving in such a way that it reflects their loud, fat, lazy, and undisciplined personality. It is most often done in cars and vans from the 80s or late-model trucks. Fat-drivers always look unhappy in their automobiles.
"I tried to take a left into the parking lot, but some fat bitch was fat-driving down the center blocking both lanes."
"I wanted to back out, but some 400-pound guy in a Festiva is stopped behind me eating a chalupa. I honked so he'd pull forward, but he just looked at me while he struggled to breathe."