Authorities in Illinois busted an auto theft ring, some of which were made up of cousins and siblings, that involved more than 200 vehicles worth more than $4 million, NBC5 Chicago reported.

According to police, luxury vehicles such as Mercedes-Benzes, BMWs and Cadillacs were stolen after they had been returned from a lease. The cars were then re-tagged with Canadian and out-of-state VINs, which were used to apply for new titles in Illinois.

How did they do it? According to cops, they posed as transport workers with car carrier trucks, showing up at car dealerships with what seemed like the right paperwork for dealers. When cars are returned to a dealer from a customer's lease, the car is often picked up and taken to auction, so the procedure all seemed fine to dealership personnel.

But, such a large volume of applications for these cars aroused suspicion and, after a little while, investigators turned up 100 fake titles. The thieves then began stealing Social Security numbers instead of using fake VINs, but authorities were ultimately able to arrest and charge 21 people in connection with the ring.

"While it may not be perceived as the most heinous of crimes, auto theft has increasingly become a more sophisticated and organized crime involving not just the theft of a vehicle, but also other types of fraud such as identity theft, forgery, and loan fraud," said Cook County State's Attorney Anita Alvarez.

Off this massive heist, dealerships will be putting in place some new procedures when the transport trucks show up to prevent being taken for a ride.

But how can individuals best prevent their prized wheels from being stolen? It's tough to foil the really sophisticated thieves. But there are things you can do to dissuade the common knuckle-head car thief, or the thief trying to break into your car to steal your stuff.

1. Always park in a well-lit, populated area, such as a busy parking lot or secure garage. Not only is this safer for your car, but it is also safer for you walking to and from it. Don't assume the leafy suburban street is a safe spot. That's a favorite spot for car thieves.

2. Double check that your doors are locked, windows are rolled up and never leave an extra key in or around your car. If you plan to leave your car all day, consider unhooking the car's battery cables.

3. Do not store anything of value in your car. Not only is it an open invitation for crooks, but car insurance won't cover these items if they're stolen.

4. Think about installing a GPS-enabled device that can instantly track your car, if you're one of the unlucky ones and your car is stolen. Not only can this reduce your insurance premium, but modern devices allow you to find your car in the process of being stolen, rather than after it's been stripped for parts.

5. Don't park at the beach or a park and move valuables from the car to the trunk. Thieves stake out these places, and will see you, making the move an invitation to steal your car and or your stuff.

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