dipping
n.— «Baeza’s passengers said Gonzalez’s van, which was alongside theirs, was “dipping,” a street term for a driver hitting the gas then braking and swerving to make it rock.» —“Man captured, admits killing father-to-be in February” by Harry Harris, Laura Casey in Oakland The Argus (California) Aug. 9, 2005. (source: Double-Tongued Dictionary)