I offer this and do not claim that this is 100% correct, but I don't think it is 100% nonsense either. Do your own research and if this is true.... 🙄🙃

I can also say that the first video is not soot from cars or trucks, because that is not magnetic, so I still wonder how it got there:

Soot (soot) from exhaust gases is not magnetic in itself. It consists largely of amorphous carbon, which is diamagnetic — so very weakly repelled by a magnet.

However, there are two nuances:

Trace amounts of metal: Fuel from combustion engines sometimes contains very small amounts of iron and other metals (from wear, additives in fuel, etc.). Studies have found iron nanoparticles in carbon nanocapsules in soot, which can exhibit superparamagnetic behavior. However, this is so weak that you would not detect it with an ordinary magnet.

Artificially made magnetic: Soot can be made magnetic in the lab by impregnating it with metal salts (iron, nickel, cobalt) and heating it, causing magnetite or metal nanoparticles to form on the surface. But that's a laboratory procedure, not what happens in an exhaust.

Bottom line: You won't be able to attract soot from a car or truck exhaust with a magnet.