TODAY | December 09, 2013
>>> this morning on rossen reports a car scam taking consumers for a ride. they have figured out an easy way to rip you off. jeff rossen is here to expose how they do it. good morning.
>> reporter: good morning. when you go to buy a used car you look for the price and the condition. you want a car with lower miles . it's more reliable and lasts longer. criminals have been tricking people for years rolling back the mileage and then selling you the car for more money. now police say the scam is growing. according to a new report nearly 200,000 car odometers are rolled back every year milking americans out of 7$760 million. we're under cover watching this car sell from across the street. the ad says it's a great luxury sedan with 85,000 miles and that's what the odometer shows too. but this car has a secret.
>> it has 250,000 miles .
>> this is online and somebody could buy it.
>> reporter: that's right. 250 thousands. nearly triple what the odometer says. so investigators from california's dmv set up this sting posing as a buyer. as the seller shows off the honda, he has no idea he's about to be arrested. we're there as police move in. authorities say he has been part of a major odometer roll back ring.
>> jeff rossen from nbc news. state records show this car has 250,000 miles on it but yet you're selling it with 85,000 miles . how did that happen.
>> this is when i bought it, how many miles on it.
>> you didn't roll that odometer back?
>> reporter: but this isn't the first time he has been arrested for rolling back odometers. convicted just months ago of felony theft.
>> you have already been convicted of a similar crime once. is that what's happening again here.
>> can you close the door ?
>> reporter: he pled not guilty to the new charges.
>> this is a safety concern for everyone because people are buying vehicles with 300,000 miles on them and believing they have 75,000 miles on them.
>> anything can go wrong.
>> anything can fail and they won't find out until it's too late.
>> now investigators say it's easier than ever for crooks to do it. why? most newer cars have digital displays. simple to hack with little devices like this. widely available online.
>> you plug it into the car, select the vehicle make and model, and then change the odometer to whatever you want .
>> reporter: watch this youtube video , just the click of the device and this car goes from over 200,000 miles to 37,000.
>> you type in whatever you want and it pops up there.
>> that's right. it overrides the entire computer.
>> reporter: it's effecting families nationwide.
>> what has this turned into for you?
>> a real nightmare.
>> reporter: that's ryan barber. when he turned 16 his dad went online and bought him this honda civic showing 42,000 miles but they later found out through service records it really has closer to 140,000 miles .
>> do you feel ripped off?
>> ripped off. lied to, betrayed.
>> reporter: they had to shell out hundreds for expensive repairs all for a car worth half what they paid for it.
>> what do you make of this practice of what they're doing?
>> they're thieves and it's not fair.
>> reporter: so how do you avoid becoming a victim? here's the takeaway. before you buy, always ask for the car's service records . also have a certified mechanic inspect the car. they can even check the internal computer to see if the odometer has been tampered with and there's a way to check the odometer history for free on car fax. all you need is the car's vin number . we have a link on our website so you can do it right now at today.com. hope it helps. back to you guys.
>> jeff, good advice. thank you.