How do I convince my mom to let me get an old car or truck?

My daddy is all for an old classic, but my mama is not so sure. Me and my daddy have come up with ways to make an old truck safer for me to drive. But she still won’t truly answer a “yes” or “no.” She wants me to have airbags, good engine, etc. I want to work on an old classic with my daddy. Probably by the time we had it finished, I would have my license. I’m a freshman right now..
Anyone have any ideas of ways to convince her that me and my daddy have everything figured out???
Thank y’all so much!!