Everything about this is a scam. Mechanic came hours late, claimed they couldn't perform the service due to a bolt I hate (it's the same bolt on every year, make, and model), then offered to install it on the side for cash another day. Now they're trying to charge me for the service and part (which the mechanic took with them). This was a scam from the start by the mechanic and the website. Avoid at all costs, literally.