Last October, when Craig Wonderlick dropped off his black 1956 Ford Thunderbird at Custom Classics, an Upper Marlboro shop specializing in restoring antique and classic cars, he expected it to be returned in "showroom condition."

Today, the Northwest Washington resident has neither his $15,000 car nor the $7,000 in cash and auto parts that he gave Custom Classics. Earlier this week Wonderlick was told his car had been stolen from the restoration shop.

After about two years in business, Custom Classics was closed this summer by the fire marshal's office because the company did not have a necessary permit.

Several customers' cars were left on the lot.

Wednesday, Wonderlick and 15 others with complaints about Custom Classics testified at a hearing called by the Maryland State Attorney General's Consumer Division and the Prince George's Consumer Commission.

At the hearing, which lasted for nearly six hours, witnesses testified that their cars had been stripped of valuable auto parts while at the shop, shabby restoration work had been done, their cars had been driven long distances while they were purportedly being worked on, and some had not been returned at all.

"This is a wild one," said Assistant Attorney General Jeffrey Werner, who represented the complainants. "It's almost like the Wild, Wild West."

According to Werner, 40 or more complaints have come into his office and that of the Consumer Protection Commission from car owners who lost a total of around $100,000 in the past year alone.

Shop owner Carole Young has been given 30 days to defend herself. Neither she nor her attorney returned repeated telephone calls from a reporter, and a family member said Young would have no comment.

The two consumer divisions are asking a hearing examiner to order that Custom Classics stop engaging in unfair trade practices and "make good for harm caused by them." But Werner could not say whether complaining former customers will ever get their money back.

Besides the consumer complaints, Werner said county government officials noted in several affidavits that Custom Classics did not have a fire marshal's permit to spray paint, a use and occupancy permit for its building, or a motor vehicle repair license, all required by law.

In addition, the Old Marlboro Pike location of the restoration shop was not zoned for an auto repair business.

"In this whole affair, there just seems to be a callous disregard for any law," said Werner.

At the hearing, Alan Fleishman of Bethesda testified that he left a $1,000 deposit with Custom Classics when he dropped off his 1966 Mustang in June. About a month later, the Montgomery County Police called to tell him they had found his car on the side of a road near Rockville.

When he went to pick up the car, the inside was wet, the upholstery damaged, a coat hanger was wired to the throttle, the gas tank was empty and the hubcaps were gone.

James P. Harris of Mechanicsville, Md. said his 1965 Mustang can no longer be driven. Harris said that when he picked up his car in April, it had dents in the body, no anti-freeze, a dead battery, and was covered by peeling paint.

Dawn Crafton of Rockville noted in an affidavit that in the six months her 1970 Cadillac was kept by Custom Classics, someone drove it nearly 3,680 miles. When she went to pick up the car in August 1978, she said, she learned that Young had gone to the beauty shop in it.

In October, when Crafton finally got her car back, she was able to drive only seven miles before it stopped, she said.

"The people in that hearing weren't just your average guy on the street," Craig Wonderlick said later in an interview. "You had a doctor, a taxidermist, and other professionals out there. They weren't stupid people. Nobody was uneducated, but everybody was taken."