Image: Car salesman showing couple new silver hatchback in car showroom, opening boot, smiling, side view - Juice Images, Cultura, Getty Images
What do customers do and say that irritate car dealerships?

The website Reddit asked car salespeople to weigh in on this. What's something you don't want customers to know when buying a car?

What took place was a wide-ranging discussion on the frustrating and often intimidating process of negotiating for a new or used vehicle. Overall, the consensus was the same: People who do their research and come armed with information stand a much better chance at nabbing a great deal. And when you're negotiating on a car, one of the best advantages you have is patience.

From that discussion, here are eight moves that drive car salespeople crazy:

1. Using your phone to check prices. "As a former car salesman our greatest fear was your smartphone," one contributor wrote. "If we gave you a number and you had a smartphone in your hand with Autotrader or some other site pulled up, we were neutered."

2. Asking for the sales manager. The salesperson approaching you on the lot has no power. The sales manager is the one making decisions, and customers can ask to speak directly to that person. "You won't believe how many times we were told what to say to a customer," wrote one person who said he was a former car salesman. "I started hating myself. I even started smoking and my anxiety was through the roof."

3. Calling in to check prices.
Customers call up dealerships, say they have other offers on a car and ask for that dealership's best offer. "Basically, the customer actually makes the dealer give the lowest out-the-door price they're willing to," wrote one contributor.

4. Asking for the Carfax report.
Carfax is a company that keeps a database with background information about specific vehicles. "CarFax is pretty much extortion for dealerships," wrote one person. "They have created a semi-false sense of security for consumers who MUST have the CarFax stating that their sweet used ride is not actually a lemon, when in reality CarFax can and does make a lot of mistakes -- and the dealer must pay for the service regardless."

5. Lying. Car salespeople have zero trust in buyers, one contributor wrote. Buyers lie about whether a trade-in has been in an accident. They lie about getting a better price from another dealer. They promise to show up the next day and never return. They spend hours negotiating and then walk away. "So everyone who says sales people are scum, customers are 10x worse," that person adds.

6. Obsessively inspecting a used car. Dealerships will do anything to get a used car looking brand new, but appearances don't hold up. "Our repairs are sometimes just a quick patch not meant for the long haul," wrote one contributor. "When you buy a used car, make sure you check every square inch of the body to make sure nothing is awry, and ask to see a list of repairs done on the car."

7. Shopping around for financing. The finance department is one of a dealership's major profit centers. Dealers often make more money on the finance than on the car itself.

8. Skipping the add-ons, like protection for the car's paint. Those packages are another profit point for a dealership. "Paint protection packages (and even many undercoatings) are a fancy way of saying 'special car wax,'" wrote one person who claimed to have worked for a dealership for six years.

More on moneyNOW