HOUSTON - Police say there are about 40 cars stolen every single day in Houston - that’s why Houston Police offer a service called “VIN etching” for free.

It’s where officers etch your vehicle identification number into each window. The service only takes about ten minutes to complete.

VIN etching is supposed to deter thieves and help police investigate car thefts. Police say you can even get a discount on your insurance if you have it done as an anti-theft measure.

It seems like a no brainer, but does it really work?

The Texas Department of Motor Vehicles Automobile Burglary and Theft Prevention Authority does recommend getting it done. In fact, it funded 140 free VIN etching events across the state last year.

However, officials couldn’t offer any hard numbers to show how well it works. It’s because they say it is difficult to count how many cars are not taken.

Houston Police Department Sgt. Tracy Hicks says he’s seen first-hand how the markings can help investigators prove car parts are stolen, especially when they bust operations like chop shops.

“I know it’s stolen. You know it’s stolen. But there’s no proof it’s stolen, because manufacturers don’t mark their stuff,” said Hicks.

So the answer is yes, having your VIN number on every window does help when it comes to car thefts, but you have to take investigators’ word for it.

“There’s alarms, steering wheel locks, kill switches, tracking,” said Hicks. “Can they all be defeated? Yes. A wrecker can steal your car anytime he wants. The whole idea is to layer these different approaches so a thief says, ‘you know what, this car just isn’t worth it.’ That’s the whole idea. Make it so he passes up yours and goes for someone else’s.”

So what about getting an insurance break? The Insurance Council of Texas says it is up to each individual provider.

KHOU 11 News checked with a handful of insurance companies. All recommend VIN etching as a useful anti-theft tool.

Geico, State Farm, Nationwide, USAA, and the Texas Farm Bureau do not offer discounts on policies in Texas.

Allstate does offer a discount for customers who get VIN etching done on their vehicles, but the discount amount depends on the policy.