SIT DOWN, DMX. JUST SIT DOWN. DMX was arrested at his Arizona home yesterday after traffic cameras on a suburban Phoenix freeway caught his bright yellow, 1966 Chevrolet (with a big DMX decal on the windshield) on three separate occasions going 100, 101 and 114 mph in a 65 mph zone. His lawyer said he had no comment, but we can probably guess his defense: “It wasn’t me!” [SP]