As any salesman knows, you gotta show the product.

So, drawing a lesson from Madison Avenue, Northern Virginia's business and political leaders put on a polished presentation yesterday for the customers who count: about 20 visiting state legislators who set priorities and control spending in the Virginia General Assembly.

In a bus tour that swept through Prince William, Fairfax, Loudoun and Arlington counties and ended in Alexandria, the lawmakers -- members of the House Appropriations and Senate Finance committees -- got a look at the region that was described to them as "the economic engine of Virginia."

The timing of yesterday's tour was not haphazard. In January, lawmakers convening in Richmond will hammer out Virginia's two-year spending plan. Northern Virginia is trying to get a leg up in the competition among the regions for state dollars.

"It's all designed to sell your wares -- or sell your needs, more specifically," said Del. Vincent F. Callahan Jr. (R-Fairfax).

Accompanied by two state troopers on motorcycles, their sirens wailing, the Metrobus carrying the lawmakers sped through red lights at Tysons Corner, hurtled down the Dulles Access Road and rumbled across landing strips at Dulles International Airport.

All the while, the lawmakers, accompanied by a gaggle of high-ranking staff members from the state transportation department, the Washington Metropolitan Transit Authority, the Center for Innovative Technology and others in need of state funds, were lectured, charmed, sweet-talked and coddled by some of Northern Virginia's most persuasive business and political leaders.

There was Earle C. Williams, president of BDM Corp., a Tysons Corner defense contractor, who extolled the benefits to the state of the economic boom that has made Tysons one of the largest office centers in the East -- and reminding the legislators that more needs to be done on road financing.

There was Jim Wilding, director of Metropolitan Washington Airports, touting Dulles as the fastest-growing airport in the nation, describing ambitious expansion plans -- and thanking his visitors for their help in making it possible.

And there was developer Thomas Hirst, who traced the boom in commercial development in the Reston area to the Dulles Toll Road -- which was approved through a bill sponsored by Hirst's father, Democratic state Sen. Omer L. Hirst of Fairfax, now retired.

For all the tour organizers' efforts, the speeches and the hoopla may not make much difference in the end.

"I'm not going to get all unglued because of this tour," said Robert B. Ball Sr. (D-Richmond), the second-ranking member of the House Appropriations Committee. "Every time I see high-tech {projects like the Center for Innovative Technology} up here, it ends up costing me money. We're looking for some returns."