Car dealers have almost completely stomped out the Internet sites that promised to sell cars directly to consumers, according to Forbes Magazine. Now they are exploiting

computers and the Internet to improve service and boost volume, especially for used cars.

Not that life is easy for dealers. Scores get

merged out of existence or go bankrupt every year. Their gross profit margin on new cars has been falling for 40 years, to 6 percent last year.

Strong vehicle sales (17.2 million sold last year) have shielded them from worse times, but sales will slow a bit this year. That's why, according to Forbes, it's urgent for dealerships to replace the gross profits they used to get on new-car sales.

One old standby is to get the buyers back in the store for higher-margin transactions like servicing and parts sales. The National Automobile Dealers Association (NADAS) estimates service and parts made up 12 percent of dealer sales last year -- but 47 percent of profits.

Another source of income is used cars, where comparison shopping on the Internet is a little tougher. And then, some dealerships are turning into gift shops, Forbes says.