Green’s Dictionary of Slang

(US) energetic, aggressive.

1957		‘Ed Lacy’ Lead With Your Left (1958) 11: ‘Dave will drive you, he’s a speed boy.’ ‘Regular hot-rod lad, I bet,’ Homicide said.
1957		M. Shulman Rally Round the Flag, Boys! (1959) 46: Stop running around with those hot-rod Romeos.
1968		L. Wolf Voices from the Love Generation 46: I sought out a very mechanized, hot-roddish, leather-jacketed group in Albany, a gang.
1972		E. Grogan Ringolevio 405: There were some hot-rod country boys in the place, hanging on the juke-box.
1990		(con. c.1970) G. Hasford Phantom Blooper 15: A few weeks ago you were the hot-rod king of some hillbilly high school, stumbling around in front of all the girls and stepping on your dick.