The first made-in-U.S.A. Volkswagen rolled onto a gold-carpeted stage yesterday and two men snapped in its plastic grill, signaling the start of American manufacturing operations by Germany's biggest auto maker.

The first American VW, a white subcompact Rabbit, probably will go back to Germany to the corporate museum, but by June or July American VW dealers will be selling Rabbits from Pennsylvania, VW executives said.

Ultimately the Westmoreland County plant is designed to turn out 200,000 cars a year, enough to help Volkswagen recapture the 5 percent of the American auto markert it held in the heyday of the Beetle.

Now, however, the plant's more than 1,000 workers are assembling only 10 or 15 cars a day. That rate will multiply until the 400-cars-per-shift, two-shifts-a-day capacity is reached, said Richard Dauch, general manufacturing manager.

VW Chairman Toni Schmuecker said the American plant will not immediately give VW the 560,000-cars-a-year sales it enjoyed in 1971. Volkswagen sales last year were less than 2 percent of the market - 260,000 cars - and Schmuecker said the company had "no chance in hell to reach 5 percent" without an American plant.

He predicted VW will capture 3 percent of the U.S. auto market within two years and "will go all out to reach 5 percent before I go into rtirement" in 1985.

Voldswagen's U.S. sales have slipped largely because the declining value of the dollar has pushed the cost of an imported Rabbit into the $5,000 range, forcing the economy car to compete against bigger Fords, Chevrolets and Plymouths.

Stabilizing the price of the cars is the first goal of the American manufacturing operations, VW executives said yesterday.

They refused repeatedly to say how much the American Rabbit will sell for. "For a considerable period of time," American Rabbits "will not be less expensive than cars coming from Germany," Schmuecker said.

Apparently one reason VW is not talking price is that all the American Rabbits are 1979 models and other auto makers have not yet set prices for next years cars.

Another factor, Schmuecker pointed out, is that 40 percent of the cost of the American car goes for imported parts. The continuing weakness of a the dollar still is pushing up the cost of these items.

As VW finds more American parts suppliers, the imported content of the Westmoreland-Rabbits will drop to 20 percent: only the engine and drive train.

The first Rabbits rolling off the assembly lines had conspicuous Goodyear tires, rectangular headlights like a For Fairmont, and baby blue plush carpet made by a major supplier to Detroit.

The soft carpet replaces the Teutonic tweed - or basic black rubber - of imported Rabbits, and the matching blue seats have a plumper look than the imports' scintifically configured but less enticing versions.

The Americanization should make Rabbits more salable, commented J. Stuart Perkins, president of Volkswagen of America, the distributer.

VW production workers, however, will not so quickly match the pay of their Detroit counterparts, who earn about $7.50 an hour under United Auto Workers contracts. The UAW has yet to organize the New Stanton plant, and Dauch said VW workers now average about $5.60 an hour in wages.

"This plant could not exist if it started out at party" with UAW wage sales said James McLernon, president ot of Volkswagen Manufacturing Corp. of America, the subsidiary of Volkswagenwerk AG, which actually builds the cars.

McLernon and Dauch refused to discuss their expectations so far as the UAW goes, but said they have made no deal with the UAW to seek wage scales lower than those paid by other manufacturers.

VW officials also defended their minority hiring record, saying "nearly 9 percent" of the newlp hired workers are minirity group members. They said 80 percent of the workers come from four counties around the plant where unemployment is above 40 percent.

The prospect of jobs led Pennsylvania to build a railroad and a freeway into the plant and to buy an unfinished plant from Chrysler Corp. and lease it to VW.

pennsylvania Gov. Milton Shapp said yesterday the plant will produce $80 million in additional taxes for the state in the next five years.

In addition to the 4,500 jobs that will be created when the plant reaches full employment, Shapp said an additional 15,000 jobs in Pennslynvania will result from spin-off projects, and nationwide some 25,000 jobs will be created by VW's $250 million investment in America.