I have a relatively simple question that I haven't found an answer to yet. How much do the stock wheels and axles weigh right out of the box? I know there's going to be some variation but need a rough idea. I forgot to weigh my son's car with the wheels and axles at the construction workshop our pack had, and I don't have easy access to a scale. I'd like the car to be as close as possible to 5 oz at check in. Thanks.