Car buying in California could become a little less of a headache starting in October under a new law that aims to end deceptive add-ons and ban no-return policies for certain cars.On Oct. 1, the Combating Auto Retail Scams (CARS) Act takes effect. According to the California Department of Motor Vehicles, this will place robust consumer protections on auto dealers in the state.These changes aim to make the entire car-buying process easier, starting with the initial communication, where the total price must be shown in any ad or written communication for a specific vehicle or financing terms.Dealers will also be limited in the types of add-ons they can offer. For example, they will no longer be allowed to offer "worthless add-ons," such as oil change plans for electric vehicles, according to the DMV.The California New Car Dealers Association opposed the legislation when it was introduced, though it said it has been working to make sure all its members are prepared for the soon-to-be-implemented changes."This is the biggest change to how cars are sold in California since 2005. It adds time and cost to an already burdensome process because dealers must now merge these new requirements with the many disclosures the state already requires," said Brian Maas, president of the California New Car Dealers Association, in a statement.In the used car space, California is adding a three-day cool-off period that lets people who buy from a used car dealership return their vehicle for a full refund within the first three days of ownership.Advocates say this allows buyers to bring the car to an auto mechanic to have it professionally inspected."Consumers in California, for the first time, will have this new right that empowers them to return the [used] car for any reason. You don't even have to give an explanation, and the dealer is required by the CARS Act to give you a refund," said Rosemary Shahan, president of Consumers for Auto Reliability and Safety, which advocated for the bill. "They're allowed to charge a restocking fee between $200 and $600 depending on the price of the car."ABC10 asked what protections are in place to ensure a consumer doesn't abuse this."You can't trash the car. It has to be basically in the same condition," Shahan said.The law also includes a mileage cap limiting how much a person can drive their used car before returning it.State senator Ben Allen (D-Santa Monica) authored the new law, saying the goal was to bring more transparency to the car-buying process, especially for dealerships that use deceptive practices."We have seen some horror stories popping up in some dealerships that have been getting increasingly deceptive in their offerings," Allen said at a press conference Tuesday.One such horror story came from David Lappen, who lives in Sen. Allen's district and shared his experience at the press conference, highlighting the new regulations when he tried to purchase an electric vehicle.Lappen, an electrical engineer who built an electric car in the 1980s, said he had a dismal experience trying to buy a used EV when he was told it would cost $5,000 more than the dealership advertised."I asked him, 'What is this about?'" Lappen said. The dealership associate told him it was for a number of dealer options, he said, including etching the catalytic converters and lifetime oil changes for free."EVs don't have catalytic converters…And you don't need oil changes for EVs," Lappen saidLappen said that from that experience, he walked away from the dealership and wasn't harmed by the practice, but many people who aren't as aware or don't have time can end up paying more for unnecessary services.ABC10 asked if the CARS Act could result in higher prices for used cars, with dealerships – having to advertise the out-the-door price – just listing the car at the final price they would've charged before, minus the haggling."This is about transparency," Allen said. "In the end of the day, the market will work the way the market works, but when I'm a consumer with limited time…I want to know upfront what the car is going to cost me."Backers of the CARS Act said they hope other states implement similar protections in their own states, while similar efforts have stalled on the federal level."California is not just going to watch on the sidelines as consumer protections are destroyed," said California Business and Consumer Protection Agency Secretary Rohit Chopra "We are going to use our own muscle not only to protect people in California but really to protect everyone across the country."WATCH ALSO: Nearly 6,000 California drivers lost licenses after DMV retest orders. Now a lawmaker wants an audit