An expedition to the nearest car dealership can make even the most confident of buyers anxious. Dealers bring a barrage of backroom talk, endless options-list add-ons and a flurry of financing provisions. The results of hours of negotiations may be a buyer who stumbles – or drives – out ruffled, and rarely relieved. But it doesn't have to be that way.

BBC Autos canvassed, the question and answer community, for members’ hard-won wisdom about negotiating with dealers, including tips from former salespeople. Their suggestions might give car buyers a touch more mettle the next time they go head to head with the pros.

Negotiating the trade

Former car salesman Leonard Kim says the dealer is focused on four main points: vehicle trade-in price, the cost of the new car, the down payment and the monthly payment. It’s what dealers refer to as the "four square".

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"There is a 100% fact that you will not get the [Kelley Blue Book] pricing of the fair market value for your vehicle,” Kim says, referencing the authoritative source in the US for used-car pricing. “Why? Because trade-in prices are based off of what your car will sell for auction." To maximise the remaining value in your vehicle, he suggests going to large consolidator dealerships – which, through their vast databases, have the means of matching a customer to your trade-in – or sell the car yourself.

That last bit of advice is echoed by the US Federal Trade Commission (FTC). "Though it may take longer to sell your car yourself, you generally will get more money than if you trade it in," the FTC website notes. The agency also suggests estimating the value of your vehicle first via resources such as Kelley Blue Book, but if selling privately does not appeal, one should wait until the price of the new car has been negotiated at the showroom before broaching trade-in discussions around your old vehicle.

Aim below invoice

To get the best deal on a new car, request to see its invoice price; most dealers take such a request as a sign that the shopper means business. "Your goal is to get them to sell you the vehicle at that price that is listed there or below it," Kim said. Invoice is what the manufacturer initially charges the dealer for the vehicle – though the price ultimately paid by the dealer may be significantly lower than invoice, when rebates and performance-based incentives are factored in, according to the FTC, which helps bolster the dealer's profit margin.

The difference between the manufacturer’s suggested retail price (MSRP) and invoice usually varies between 10% and 20%. Armed with this knowledge, a shopper may dive into a negotiation with leverage. That isn’t to suggest a salesperson will roll over.

"Be patient about the negotiation process,” the website for the National Automobile Dealership Association (NADA) says. “It takes time to arrive at an agreeable selling price, and be prepared to leave if you can't reach a price that's right for you."

Finding the right financing

Whether you're buying a new or used car from a dealer, shop around for the best financing. Dealerships may offer to do this for you, but they do not always produce the most competitive rates. A car salesperson is in the business of selling a car at a competitive price; a bank is in the business of providing financing at an attractive rate. The twain don’t always meet.

Quora user Jason Lancaster said, "A great way to avoid the drama in the finance office is to get a loan from your local credit union. However, if you're buying a new car and you want to take advantage of a special interest rate (like 0%), you're going to have to work with the dealership's finance person."

When to buy

Opinions vary on when the best time to buy is, though a handful of Quora users swear by shopping at the end of any given month. Brad McCarty, a former car salesman, said, "End of the month is an absolutely great time to buy. Yes, salespeople have quotas. No, that doesn't mean that you should try to take unfair advantage of that."

It is advice shared by personal finance and insurance companies. "Dealers and salespeople have monthly and quarterly sales goals they must meet in order to qualify for certain bonus levels,” the website for USAA notes. “So the end of the month or quarter is a good time to go shopping."

Quora users also suggested time-worn tips such as knowing exactly what car you want – and what features you’re willing to live without – before buying. Combining all these suggestions can give shoppers better footing in a negotiation.

But best to leave the antacids in the glove box, just in case.

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