Being addressed by your first name isn’t a form of rudeness. Why should anyone care that you’re a doctor outside of the office? I too am often called Dr, but I’d never expect a salesman or anyone else to know that or care, unless I’m actively doctoring him. That being said, if it was a reasonable price on a good car that would be difficult to find again, I would probably stick it out and get some free floor mats or something to compensate you for your time. If this isn’t a third car, and you need it to get around, I’d shop elsewhere. It shouldn’t have been posted for sale until it was rightfully for sale.