While we do not require you to provide us with a VIN#, we highly recommend it. When you provide us with a VIN#, we will verify the parts ordered are correct for your application. If you are ordering parts for multiple vehicles, you can put the VIN#s into the comments section and let us know which parts apply to which vehicles and we will still verify their accuracy. The catalog that is used online is not the catalog that we use from Hyundai. If no VIN# is supplied, we can not guarantee the parts are correct for your application. Parts are still returnable as long as they are returned within the 30 days (see our return policy for details). We just want to get you the correct parts the first time as to not inconvenience you. You can contact us to check the accuracy of the parts you are ordering at any time. Thanks.