Used car salesmen have a bad reputation.
Because the law considers anything they say to induce to to buy the car as puffing (meaning they can’t be held to claims made) they stretch the truth.
Only what is reduced to writing in the 4 corners of the contract binds the seller.
So if you are told the car was only driven on Sundays by an old lady to drive to the market and actually that Mercury Grand Marquis was a livery vehicle, you lose.
As for mechanics they don’t care if they get you under the hood or in the trunk