not sure the year of lime green Roadmaster, but sources indicate somewhere in '54-'56, in early "Fitz & Kaufmann" before the more numerous/memorable Pontiac campaigns (late 50's thru about 1971).
More mid-50's Buicks in cool night-time illustrations are among the duo's early work. The last one, the white car, is 1956 per the rear license plate cue.