Been there, done this. :) Scary is right but here's a surefire test to get you and your 15 year old on the same page. The quiz for teens buying an auto is a short one. 1-What are all the different costs associated with buying a car? How much are they? 2- What are all the different costs associated with operating a car? How much are they? Go over your teen’s list and find out if they left out any of the costs on either list. (Leave off accidents, for now.) If costs are not considered and planned for, a rude awakening is in store. Your teen may think that since they have been stashing away money for months, they finally have enough to go car shopping — or so they think. Use this golden opportunity as a teaching moment for earning, saving, spending... and yes, they should put aside 10% of their car savings to give to charity. Hope this helps!