Fairly soon, the car-rental industry simply may stop debating whether its customers should be offered the often-criticized collision damage-waiver (CDW) charge on rental contracts.

That's because through legislation, the actions of credit-card companies or simply bad publicity about the CDW's high cost, this form of accident and theft insurance soon may disappear.Car-rental companies insist the CDW is not insurance, although it looks and acts like it. By adding it to the other charges for a car rental, at a cost of $9 to $12 a day, a renter theoretically is free of liability for any damage or loss involving the car, unless the company decides the renter was negligent.

The CDW charge often is sold in a high-pressure way, by a grim warning to a renter.

But many renters don't need to purchase the CDW because their personal auto insurance offers precisely the same coverage. Many business travelers' employers also have group insurance policies that make buying a CDW unnecessary. Using certain credit cards for the rental can accomplish the same purpose.

At some companies that rent mostly to vacationers, including Alamo, well over half the customers accept the CDW. At Hertz, which rents more to business travelers, about 30 percent buy the CDW.

The high cost and the high-pressure sales tactics used to get customers to accept the CDW led the National Association of Attorneys General and the legislatures in several states to develop a keen interest in CDW sales in 1988.

The law-enforcement chiefs also have been questioning whether laws are needed to govern the way additional charges, besides the CDW, can pile up on rental contracts, often making the actual cost come to double the advertised daily rate.

Charging $10 to $12 for a half-tank of gas, for instance, no matter how much fuel is in the car when it's returned, is one of the more common additional charges.

In early December, the National Association of Attorneys General gave preliminary approval to guidelines designed to limit abuses in the sale of the CDW and other car-rental costs.