Green’s Dictionary of Slang

buick v.

also call Buicks, scream Buick
[echoic]

(US) to vomit.

[US]Eble Campus Sl. Fall 2: buick – vomit when drunk.
[US]Eble Campus Sl. Mar. 2: call buicks – vomit.
[UK]M. Belmonte Compter Science and Why (1993) [Internet] I was struck with [...] the plethora of words and phrases meaning ‘vomit’ and/or ‘to vomit’ [...] At most American colleges and universities, a weekend cannot pass without seeing multitudes [...] scream Buick.
[US]Eble Sl. and Sociability 40: Onomatopoeia, or echoism or imitation of sound, accounts for many slang terms, including these for ‘vomit’ – barf, buick, earl, ralph, and yuke.

In phrases

ride the buick (v.) (also sell buicks, sell the buick, go to Europe with Ralph and Earl in a Buick)

(US) to vomit.

[US]Eble Campus Sl. Apr. 4: sell buicks – to vomit.
[US]Eble Campus Sl. Mar. 7: toss groceries, toss cookies – vomit (synonyms: [...] go to Europe with Ralph and Earl in a Buick).
[US] P. Munro Sl. U. 159: ride the Buick to vomit.
[US]Eble Campus Sl. Apr. 7: sell buicks – vomit.
[US]College Sl. Research Project (Cal. State Poly. Uni., Pomona) [Internet] Selling buicks (verb phrase) Vomiting from alchohol consumption.
Online Sl. Dict. [Internet] sell the Buick v 1. to vomit. (‘The thought of doing Chelsea makes me want to sell the Buick.’).
[US]Hope College ‘Dict. of New Terms’ [Internet] selling Buicks verb phrase Vomiting from alcohol consumption.