Sexist Used Car Salesman

Everyone knows women don't know anything about cars. Or at least, that's what these guys seem to think. Because if a woman shows up at their dealership trying to buy a car, then they become much more likely to try to mark up the price or sell her that old Alleged Car. Something of an Undead Horse Trope, since nearly all examples are either parodies or subversions. In media, it's common for the woman to actually do enough research to know more about the car she wants than the salesman himself. Of course, he probably just thinks that it's adorable that the "Little Lady" thinks she knows anything. Until she sets him straight anyway.

This can just as easily happen (and may be more common) when women take their cars to the mechanic, who begins to make up imaginary problems and generally overcharge her just because she's a woman. It's often Truth in Television; many car salesman and mechanics will try to scam women (and just as often men) who even hint at not knowing enough about cars. A subtrope of Honest John's Dealership. See also Women Drivers, which is part of the cause of this trope.

Examples of Sexist Used Car Salesman include:

Film

Pat Buttrum plays one of these in Angels Revenge.

Literature

This tendency of car salesmen was addressed in Blink by Malcolm Gladwell. In the 1990's, Chicago professor Ian Ayers did an experiment where he send a number of people of differing sex and ethnicity, but the same age, dress, behavior etc, to try and buy a car and negotiate the best deal they could out of the dealer. White Men got the best offer, followed by white women, then black women and finally black men, who typically ended up being offered a price hundreds of dollars higher than white men even after lengthy negotiation. Bob Golomb, on the other hand, was a highly successful salesman because he didn't make assumptions and treated everyone equally. One example he gave was of a farmer who was a regular customer. "Now if you saw this man, with his coveralls and his cow-dung, you'd figure he was not a worthy customer. But in fact, as we say in the trade, he's all cashed up."

Live Action TV

On an episode of Family Matters, when Laura tries to buy a used car, the salesman insists on trying to sell her another one because it's "a pretty color." When she goes back later dressed as a man, she's able to convince him to sell her the car she wants at a discount...until he sees through the disguise, at which point she still gets a discount by crying instead.
Swiss Toni, who compares everything to making love to a beautiful woman. Even if it doesn't make sense.

Music

There's an example in Les Bidochons, though it concerns houses rather than cars. When the salesman is through explaining the merits of the house, Raymonde wants to ask something, to which the salesman gives a condescending smile and goes "Certainly, ma'am. Would you like to know about the furinture colors, or the drapes, or the...". Then Raymonde floors him with a technical question about things like what materials are used for the walls.

Web Comics

Popped up in 21st Century Fox, when Jenny goes shopping for a new Flying Car. Being a rocket scientist and astronaut, she's looking for something sleek and fast, but the car salesman keeps trying to sell her on family-cars (and cars with wide backseats) for various sexist reasons. Also qualifies as Too Dumb to Live, since he's a rabbit and she's a fox. Only the timely intervention of the rabbit's more level-headed wife prevents Jenny from making lunch of him...
This is likely a part of the reason Ash and Emily go to the used car place together in Misfile. Emily deliberately plays the sweet, naive girl who listens to everything the salesman says, and then Ash chimes in and shows him up with her savviness. The trope is Double Subverted here because Ash actually used to be a boy.

Western Animation

In Futurama this happens when Amy goes to buy a car (she's Spoiled Sweet and her parents are paying, so it's all played for laughs). It's also inverted, when a salesman tries to sell Fry a car by questioning his masculinity. A deleted scene also contains Double Subversion where the salesman points out the "special mirrors", Leela tells him to stop patronising them...and then proceeds to ask "what makes these mirrors so special?".