How can I talk my parents into letting me get rid of this?

I made a clock in a shop class last year, a nice looking one that is worth about $400-$600. It has an annoying quarter-hour chime (I had no choice in the clockworks for it) that every time it goes off, I swear I hear a rumbling in my head. So I have a deep hatred for it. Now, at this point, you’re probably asking yourselves, “What does any of this have to do with parents and family?” Well, my mom will not let me get rid of this thing. I would like to try and trade it for a car or truck, but she recently started claiming that I gave it to her, which I didn’t. She says she likes it, but I NEED (can’t emphasize that more) my own vehicle. I have some money put aside that I can use for repairs, if neccessary, and could maybe pull off insurance for it (insurance not mandatory for NH, so I could legally go without). Right now I use one of the 3 that my parents own, the car and the suv, and the pickup truck isn’t doing so great now. Now, with having such needy vehicles, and everything being 20+ miles one way in NH, I have to go at least 50 miles one way to go work somwhere. So thats at least 100 miles every working day, not including school. And I’m not allowed to use their vehicles, cause of wear and tear, which I can understand, but this is too limiting. So, how do I get my mom to part with the clock? Thank you.