The National Highway Traffic Safety Administration dropped a proposed rule into the Federal Register the other day that could be worth at least $1 million annually to the General Electric Co. and make it cheaper to buy a bulletproof car.

The proposed rule would permit firms that make vans and cars bulletproof to insert a GE product called Lexgard inside the regular glass windshield and side windows. Lexgard stops bullets, and regular glass doesn't. Lexgard weighs about half as much as bulletproof glass and is supposed to be substantially cheaper.

What's interesting is that a company has found a way for a government regulator to make it possible to sell a product despite rules to the contrary. Here's what it's all about:

Lexgard is a plastic and, like all plastic materials discovered so far, scratches more easily than glass. In fact, federal standards prohibit the use of plastics in windshields because they can't pass the government's abrasion-resistance test.

"Plastic simply doesn't hold up to glass," said NHTSA's Edward Jettner. "If abused, it gets hazy and you can't see through it; if you can't see through it, it gets dangerous." Lexgard passes the other NHTSA windshield tests with flying colors.

So what GE proposed, and what NHTSA tentatively has accepted after some tests, is a proposal to mount Lexgard on the inside of the regular auto glass. That way it could not be scratched as easily as the outside surface, and yet would provide the bulletproof protection.

GE backed up its petition with a shooting demonstration at Lorton Reformatory. Lexgard, according to Jettner, stood up impressively when bullets from high-powered weapons were fired at close range.

If NHTSA's proposal is adopted, it will take the small businesses who modify vans and automobiles off the regulatory hook. They are subject to NHTSA enforcement proceedings if they install unapproved bulletproof materials as windshields, and some enforcement actions are under way, Jettner said.

He estimated that there are about 10,000 bulletproof vehicles in the country, including armored cars and limousines, and said the market seems to be increasing slightly.