SWAMPSCOTT-A mere 10 minutes and $10 could save you $100 or more. Sound too good to be true ? well it’s not according to local police.The Governor’s Auto Theft Strike Force and the Swampscott Police Department are sponsoring a “VIN Etching Day” to mark automobiles with their vehicle identification numbers on Saturday, Nov. 1 at the Department of Public Works garage at 290 Paradise Road from 9 a.m. until 2 p.m.Detective Sgt. Tim Cassidy said etching VIN numbers into the glass is quick, safe and a theft deterrent. He explained the process involves marking automobiles with its own unique VIN number on all windows, sunroofs and T-tops. Cassidy said etching is a chemical process that uses acid, which only reacts with glass.?Etching all the glass windows of the automobile makes the vehicle less attractive to car thieves,” he said.?Car owners are given a certificate to give to their insurance company and most companies offer discounts of up to 15 percent on their comprehensive car insurance premium for vehicles that have the VIN number etched into the glass.”Cassidy said the $10 fee for the etching must be paid in cash at the time the service is provided and vehicle owners need to present a valid registration at the time of the service.?The whole process should take approximately 10 minutes to complete,” he said. “People don’t need an appointment.”