The new, sky-blue 1982 Cimarron -- the smallest Cadillac made in two generations, perhaps -- was parked outside the Homestead in Hot Springs, Va., last weekend, attracting stares.

Among the onlookers was Philip M. Caldwell, chairman of Ford Motor Co., who was seen driving away in the Cimarron to find out for himself what the competition at General Motors has produced in its line of J cars.

Caldwell's reaction wasn't immediately available, but he isn't the only one harboring curiosity about the GM J-car line that is being introduced this month -- the Cadillac Cimarron, Chevrolet Cavalier and Pontiac J-2000.

After a decade of largely ignoring the foreign-car competition, Detroit has spent the last three years laboriously bringing its sights to bear on the stream of Toyotas, Datsuns, Hondas, BMW's and other imports that have taken well over a quarter of the American car market.

The J-car line of four-passenger, front-wheel drive cars follows the Chrysler K cars and the Ford's Escort/Lynx subcompacts and sports versions in a crowded, fiercely competitive market. According to Consumers Guide magazine, there now are 18 separate front-wheel-drive small cars selling for $8,000 or less, most of them American.

Both the Chrysler K-car line and the Escort/Lynx have sold well, and auto analysts assume that GM's J cars will do likewise, although the GM cars won't come cheap. GM plans to announce prices for the Cavalier, J-2000 and Cimarron later this week, but auto analysts expect the Chevrolet and Pontiac versions will cost about $8,000 each, while the Cadillac will be priced at $12,000.

Except for a few body details, the three cars look identical from the outside. They are built for four passengers with more rear seat room than most of their competitors, and according to GM, they will have government ratings of 26 miles a gallon in city driving and 42 mpg on the highway.

GM hopes to sell the J cars on the strength of a major improvement in production quality, as the company sees it "The J car is a large step above anything we have done before," said GM President James McDonald. Although American-built cars have a significant edge over imports in strength and durability and in antirust measures, there is no denying that most consumers believe imports are put together with greater care and quality, he said. "We're just plain going to have to overcome that."

The hardest sell may well involve the Cadillac version -- in many ways a Chevrolet look-alike with a price tag expected to be between $3,000 and $4,000 higher. The comparison will be a little less obvious since Cimarrons will be distributed at first only to dealers who sell the Cadillac line exclusively.

The Cimarron comes with leather seats, forged aluminum wheels and a dashboard full of instruments. But McDonald said that the feature GM hopes will set the car apart from the rest of the line is its road performance.

GM is inviting comparisons between the Cimarron and the BMW and Audi luxury compacts, and it has strengthened and tightened the suspension of the Cimarron to make it drive like a European car.

"You have to ride it to feel the difference," McDonald says.

The Chevrolet Cavalier and the Pontiac J-2000 will be in direct competition with the Japanese compacts and the new Ford and Chrysler front-wheel-drive cars, as well as some of GM's older models. A crucial question for the ailing U.S. auto industry is out of whose hide the J-car sales will come?