Green’s Dictionary of Slang

lowrider n.2

[since the driving of such cars is illegal, they are fitted with hydraulic systems to adjust the height of the car while driving, making it appear to bounce]
(US)

1. (also lowride) a customized car, occas. motorcycle, that has been ‘chopped and channelled’ to lower the suspension and give it a generally sleeker look.

[US]Wentworth & Flexner DAS (Supplement) 720/1: low rider 1 A person who drives a car with a lowered suspension. 2 A car with a lowered suspension.
[US]E. Folb Runnin’ Down Some Lines 245: low ride n. 1. Car whose body has been permanently lowered. 2. Car whose body can be raised and lowered through the use of lifts.
[US]S. Morgan Homeboy 57: Rigo La Barba slumped on the nod in crushedvelvet front seat of his ’62 Impala lowrider.
[US]B. Gifford Sinaloa Story 218: In my closed mind lowriders are for cholos.
[US]Source Aug. 118: Three lowriders have been brought to the set to add a ’hood feel.
[US]P. Beatty Sellout (2016) 117: The bitchin’ and firme hot rods and lowriders that grace the covers of custom-car magazines.
[US]T. Pluck Boy from County Hell 173: The Challenger’s hood bounced up and down like a low-rider.

2. the driver or passengers of such a car.

E. Cleaver Soul on Ice 37: Low rider [...] the term was coined to describe the youth who had lowered the bodies of their cars so that they rode low, close to the ground [...] when these youthful hipsters alighted from their vehicles the term low rider stuck with them.
[US]J. Wambaugh New Centurions 117: Four or five heads barely showed above the window ledges which told Serge automatically that the seats were dropped and it was probably a gang car. ‘Who are those low riders?’ Serge asked.
[US]E.E. Landy Underground Dict. (1972) 122: low rider n. 1. Motor cycle rider who has his handlebars raised 16 inches above the legal limit so he looks as though he is riding low. 2. Person who drives a lowered car.
[US]E. Folb Runnin’ Down Some Lines 64: Low riders go over dere, bounce dey lift couple times.
[US]E. Little Another Day in Paradise 206: ‘Billy wants to be a lowrider when he grows up.’ ‘Lowrider? Sheeit, darlin’, full-on cholo vato loco.’.
[US]W. Shaw Westsiders 261: Old low-riders might replace these [i.e. wide tyre rims] with 14- or 15-inch rims and fatter tyres.

3. a Chicano (among whom lowrider cars are popular).

see sense 2.
[US]E. Bunker Animal Factory 11: Sure these lowriders stab each other, but if you mind your own business, nobody bothers you.
[US]S. Morgan Homeboy 226: Each on his shoulder displayed the lowrider legend, mi loca vida.
[US]J. Stahl Pain Killers 273: A low-rider in wraparound shades.

4. (orig. US black) in pl., baggy jeans with a low crotch, worn so low as to reveal one’s underpants; thus low-riding adj.

[US]G. Pelecanos Shoedog 123: Young men dressed in hooded sweatshirts and low-rider jeans.
[US]N. McCall Them (2008) 104: He passed teenagers hanging out in low–riding baggy pants.