James Bennett, 70, took his 1973 Dodge to Speedy Auto Repair on Upshure Street NW for what he believed would be fast, cheap service on a malfunctioning engine. One month later,he found the car's motor had been replaced with a "piece of junk."

When Bennett asked the D.C. Office of Consumer Protection to investigate, they found the small shop abandoned, with no trace of Bennett's repairman.

Because hundreds of unlicensed repair dealers operate illegally in the District, cases like Bennett's are not uncommon, according to Richard Alexander, the office's auto division chief.

All repair dealers are required by law to be licensed by the District consumer office, which enforces the city's repair regulations. Like other businesses, they must also have a certificate of occupancy.

Unlicensed dealers often disregard or are ignorant of the city regulations and account for the more serious complaints, Alexander said.

"They can take your money, put your car on the street and claim they never had contact with you," Alexander said.

He describes nonlicensed repair shops as "fly-by-night" or "back alley" operations with a fast turnover of personnel and a company name that seldom reflects the true name of the owner.

But many unlicensed shops are well established, thriving on the reputation of a previous owner, according to Richard Tynes, deputy director of the consumer office.

Attorney Marcia Wiss, in a complaint to the D.C. consumer office, said that Georgetown Gulf -- "a neighborhood place where they washed your windows and smiled" -- insisted on parking her stalled car on the street, but refused to pay for the towing and parking tickets that resulted.

Wiss learned that hers was one of many complaints about the new owner, who, according to consumer staff members, was unlicensed for repair work.

Bob Shelton, owner of Georgetown Gulf, agreed to pay for the charges after negotiations with the consumer office. He denied he was unlicensed for repair work, however.

Although licensing cannot ensure that a repair shop will follow city repair regulations, it can guarantee that if a complaint is filed with the office, authorities will have the information needed to locate and investigate the dealer.

"The license is something to guarantee the dealer's availability to remedy the complaint," Alexander said. Otherwise, he said, "police can't help you even if you've been criminally defrauded -- there's nobody to look for."

Of the subjects of 23 car repair complaints the consumer office received in June, 11 shops were found to be unlicensed. That number "probably" reflects the usual number the office receives each month, Alexander said.

Repair dealers who neglect to renew their licenses are largely responsible for the high number of unlicensed dealers, according to Clifton Johnson, director of licensing and registration for the consumer office.

Most unlicensed dealers are located through complaints to the city consumer office and the police consumer fraud unit. Dealers are usually given 30 days to obtain a license. After that time, the dealer is subject to arrest.

Alexander said that only about half of these dealers comply after notification. The other half claim they do no repair work, he said.

"We have to catch them in the act," he said, a practice that requires "a lot of leg work."

"What we need is an office proportionally sized to handle each case within a respectable amount of time," Alexander said.

Archie Richardson, of Automobile Owners Action Council, a nonprofit consumer protection organization, believes the city is not doing enough to enforce the licensing requirement.

There are presently 425 licensed car repair dealers in the District. Fifteen of those are franchised from large dealers; the rest are independent owners.

One way to avoid disreputable service is to ask to see the dealer's license, Alexander said. He also recommends evaluating the shop's appearance, personal service and cleanliness.

According to the D.C. Consumer Goods Repair Regulations, the consumer can expect the following services when bringing an automobile -- or electronic equipment -- to a shop for repair:

The dealer must inform the consumer of all service charges to be imposed whether or not the consumer chooses to have the work done at that shop.

A receipt with the dealer's name, address and phone number, as well as a description of the goods and the date of receipt, can assure the return of merchandise to the consumer.

The dealer must give the consumer a written estimate before repairs. The consumer should then sign the document for authorization.

The total costs for repair services cannot exceed the cost quoted on the estimate by more than 20 percent for repairs costing $300 or less, or by more than 10 percent for repairs costing more than $300. Written permission must be obtained by the dealer to modify the cost beyond these limits.

The consumer has the right to parts that were replaced while making the repair. If there is a question concerning the repair, the parts can be taken elsewhere for examination.

The dealer must sign a final bill of payment listing all work done and all parts replaced.