"We try to get prices as close to invoice as possible, minus any rebates," says Shebesta, who notes that any rebate savings are passed on to the customer.

"However, there are certain popular cars that are going to be sold for sticker (full retail price)," he says. "If that's the case, we'll tell you. The only thing we could do is make sure nothing else gets added on to the price. With really popular cars, the dealers do like to add on things which increase the final cost."

Some services may be free
You may have free access to a car-buying service -- even if you don't realize it.

Car insurance companies, credit unions and even energy cooperatives sometimes offer complimentary car-buying services to members.

"I had a car accident and totaled my car. I didn't want to buy a new one at first, but my car insurance company recommended a buying service," says Zoe Wolf of Atlanta, who used No Haggles because her insurance company picked up the tab.

"I had a new car within a week. The experience was absolutely and totally painless."

Oxsalida says AAA Auto Club South offers its car-buying service free to members. Annual memberships at AAA South are generally under $100, but each geographic region is independently operated, so rules may differ.

"Not every AAA club has a car-buying service, though, so you have to check," says Oxsalida. "Some clubs may buy the cars outright and then sell them to members."

You might do better on your own
Car-buying services can eliminate a lot of the more unpleasant aspects of buying a car. They also save you time and effort.

However, buyers who do their homework and are willing to negotiate will probably find as good a price or better searching on their own.

"You can absolutely get a good deal on your own," Fix says. "The key is doing your homework."

Many buyers can find good deals for cars through classified ads or other sources, all without having to pay for a car-buying service.

Shoppers who go it alone are likely to have better luck if they first research the cars in which they are interested.

"To learn about car values, research car sites on the Internet," Fix says. "Know the cost of any extra features for the model you're looking for."

Buyers who are properly prepared also have a big edge when they walk onto the car lot, Fix says.

"When you walk into a dealership armed with information, it makes a huge difference," she says. "The dealers know you're not there to play games."