[[DoubleStandard 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 AllegedCar. Something of an UndeadHorseTrope, 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 TruthInTelevision; many car salesman and mechanics will try to scam women (more often than men) who even hint at not knowing enough about cars. A subtrope of HonestJohnsDealership. See also WomenDrivers, which is part of the cause of this trope.
!! Examples

* There's an example in the French comic ComicBook/LesBidochons, 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.

* Pat Buttrum plays one of these in ''Film/AngelsRevenge''.
* {{Averted}} in ''Film/{{Psycho}}'': Marion Crane is ''desperate'' to sell her car and get another (in order to change her conspicuous license plate, given the theft she committed has already been reported), and has to practically beg the dealership man to get one, without even bothering to discuss the price.

* This tendency of car salesmen was addressed in ''Literature/{{Blink}}'' by Creator/MalcolmGladwell. 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."
* ''[[Literature/{{Matilda}} Matilda]]'' by Roald Dahl has Matilda's father as this, although he's HonestJohnsDealership in general and treats ''every'' customer like a sucker.
* Inverted in Scott Adams' nonfiction book ''ComicStrip/{{Dilbert}} and the Way of the Weasel'', where a young woman ''dealer'' has to deal with a sexist male ''customer''. She gets her own back by tricking him into paying twice what the actual price of the car was.

* On an episode of ''Series/FamilyMatters'', 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 [[SweetPollyOliver 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 [[WoundedGazelleGambit by crying instead]].
* ''Series/TheFastShow'': Swiss Toni, who compares ''everything'' to making love to a beautiful woman. Even if it doesn't make sense.
* One episode of ''Series/ThirdRockFromTheSun'' had the family take their car to a mechanic for maintenance. The mechanic completely ignores Sally in faovour of talking to {{Cloudcuckoolander}} Harry, going on about how women know nothing about cars. Then Sally uses a wrench to squeeze the man's balls.

* Popped up in ''[[Webcomic/TwentyFirstCenturyFox 21st Century Fox]]'', when Jenny goes shopping for a new FlyingCar. 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 TooDumbToLive, 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...

* In ''WesternAnimation/{{Futurama}}'' this happens when [[AsianAirhead Amy]] goes to buy a car (her super-rich 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 DoubleSubversion 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?".
* Inverted in ''WesternAnimation/KingOfTheHill'', where the car dealer had been tricking Hank since his teenage years into thinking "sticker price" was the norm, but was willing to accept a much lower price from Peggy.