Rc cars. I got a crappy 1/6 scale truck (newbright) for shits and giggles to see what it could all do before I fried and broke it. Ended up slowly dumping a bunch of crap into it (Batteries, lights, new controller, esc, new brushless motor etc)
Wouldn’t have been quite so bad if it was a “normal” scale rc, but parts for something 1/6 scale is pretty pricey. I could have just bought a better machine, but it was still fun and I learned a bit about rc stuff. This is the frankenRC i.imgur.com/ey1jJYX.jpg