Fuck In A Truck. This would be the guy in the huge truck that makes harassment of innocent drivers on the road his regular business. M.O. includes tailgating, taking corners with little-to-no breaking, and possessing a generally obnoxious, pissed off type of energy. Typical F.I.A.T. behavior includes (but not limited to): riding your ass for going ONLY 15 mph OVER the speed limit, then whipping around you and deafening you with his pimped out dual exhaust system, and completing the transaction by squeezing back in front of you in the 30 inches you left between yourself and the car in front of you. Also, vehicle of choice most commonly includes a decal of Calvin pissing on a ford/chevy/dodge logo adhered to the back window.
* These videos are coming directly from Youtube, they may or may not be most relevant to the word "F.i.a.t."