Owners of Fuzz Busters, Snoopers Whistlers and other radar detectors, beware in Virginia: If you drive through the state and are stopped by the police you're subject to a fine, confiscation of the device and possible imprisonment.

Virginia and Mississippi are the only states to specifically outlaw the devices, which have become increasingly popular as a means of detecting the presence of police radar units, exceeding the speed limit and avoiding speeding tickets. Virginia State Police said they have arrested 2,000 motorists for possession of the radar detection devices in the first seven months of the year.

The increasing popularity of the devices also has resulted in an escalating conflict between their owners and the police.

Some radar detector owners complain that the Virginia law is arbitrary, that confiscation is patently unfair and that they are unaware of the statute because there are no signs posted indicating detectors are illegal.

Bob Brooks, a Fairfax County lawyer and legal counsel to the BMW Club of America, said the club has received complaints about arrests. "Ordinarily it's from the guy who's traveling from New York to Florida who drives through Virginia. Since they're perfectly legal in just about every other state he has no way of knowing about Virginia," Brooks said.

Virginia State Pollice defend the law on the grounds that the sole purpose of the detectors is to enable drivers to exceed speed limits. "It's a piece of equipment that has only one purpose - to avoid apprehension," said State Police Maj. C.M. Boldin. "I don't see that the state has any obligation to a person bent on breaking the law." The Virginia Highway Department said "signs noting the illegality of the devices will be posted on major highways in the state in October.

Although they're sold under a variety of names, the radar detectors basically are small, square black boxes of size of a CB radio. They plug into the cigarette lighter or aremounted on the dashboard or windshield visor. Detectors are a combination transmitter-receiver which pick up two basic frequencies licensed by the Federal Communications Commission according to Maryland state police spokesman Bill Clarke.

Some units blink others buzz or whistle when they detect the presence of radar. Most cost between $100 and $150. It is not known exactly how many of the detectors have been sold nationwide, but Mail-O-Tire, the distributor of Fuzz-Busters, said it has sold more than 5,000 of the devices in the last 18 months.

Virginia and Maryland state police claim - and some owners concede - that the devices are frequently ineffective because the less sophisticated models don't give advance warning of police radar, pick up stray signals like home burglar alarms, and are powerless against helicopters, which have been dubbed "bears in the air."

Under the Virginia law, which has been strengthened periodically since its inception in 1962, mere possession of a device is a misdemeanor punishable by a $25 to $100 fine, confiscation and destruction of the detector and a possible 10-day jail sentence.

According to Virginia officials, motorists from most states, other than the handful with which Virginia has an agreement permitting it to pursue prosecution of traffic offenses run the risk of imprisonment if they are stopped and unable to post bond.

John Bielkevicus, a temporary resident of Greenbelt, is a Massachusetts resident who drives to Boston twice a month, where he said "driving is a cat-and-mouse game."

Until his $110 "Snooper was confiscated in Tappahannock County, Va., on a recent trip, Bielkevicus relied on it to give him a half-mile warning of police radar traps.

Before he bought the device, Bielkevicus said, he had received a number of speeding tickets or warnings. He said he hadn't known that the devices were illegal in Virginia until he was stopped by a sheriff who spotted his radar detector.

"He took me to the sherrif's office and told me I was going to have to post $120 bond immediately. I started laughing because I only had $35 with me and then I was told, 'Well, you're just going to have to spend some time in jail 'til you get it.' It was starting to look like something from 'Alice's Restaurant,'" the epic Arlo Guthrie song about a comedy of errors resulting from a simple arrest for littering.

After several requests, Bielkevicus said he was allowed to see a judge who lowered the bond requirement to $25.

Bielkevicus said he was angered by the loss of his detector and the lack of Virginia road signs about the illegality of detectors. "If the police can use sophisticated equipment to entrap you, there's no reason why citizens can't use sophisticated equipment to detect that. Absolutely, I'll buy another one. That way I don't have to monkey around with a CB unit that transmits and annoys an entire band and tells everyone where the cops are."

Sales of detectors are flourishing Radio Shack, located at $1600 Rockville Pike in Rockville, sells a detector called "Road Patrol" for $69.95 and said it recently sold out all 16 of its units within a week.

The increase in sales has apparently been matched by a tougher attitude on the part of law enforcement officials. John Jennrich of the American Automobile Association said, "There has been an unspecified increase in requests for bail bond" from AAA members caught with the radar detectors.

Jennrich added, "We caution our members that the detectors are illegal and that they are taking a risk by using them in Virginia."

Mail-O-Tire of Rochester, N.Y., encloses a notice about detectors' legal status, according to vice president Dick Rigby. Rigby added that he occasionally tells buyers how to hide the devices inside tissue boxes on the dashboard.

Proponents of radar detectors say they actually promote safe driving. "When you're driving down the road on long trips you're not always watching the speedometer," said Brooks of the BMW Club. "When your speed creeps up, the device goes off if it's in a radar field and you're automatically going to slow down, whether you're five or 50 miles over the limit."

Maryland state police spokesman Clarke strongly disagreed. "A person concerned with the safe driving doesn't need one of those things," he said. "If you're concerned with safety you can get a good cruise control device for $100, set it on 55 (mph) and just sit back and enjoy the drive."