De-rusting axles
As you can see here, I have two donor cars on my desk, a Pharodox and a Cyber Speeder. I fished both of them from my backyard, so they've rotted quite a bit. Any cheap/reliable way to de-rust the axles completely without disassembly?
Discussion
IMO better off spending $1.40 on a new car from Dollar Tree than the $20 plus in product it will take to get a "rotted" car from the backyard in shape to race.
If you want to put in the effort, you could soak them in very warm water with a little bit of Dawn dish soap, or some other brand that claims to be a good de-greaser. Let it sit 20 mins, rinse it out, roll it back and forth several times to get the wheels moving some and then do it all over again a few times. You should be able to get it rolling, but it will never be "fast"
I would start out with a Margarita, but that's just my approach. Maybe some chips and salsa.