We use it at work for various application. I will have to see about the possibility of testing some rusted cold rolled... (I do not have high hopes - Expensive machine/backlog of work)

Just some of my thoughts:

The benefits I see of water/sand blasting vs. sand blasting is the ability of the water to drive the sand particles through small part features (In my case small holes). Every part we process gets acid etched after processing.

I would be skeptical doing this with body panels because of there is a significant amount of water pressure being used. Frame/Rims should work fine I can not speak to the correct way to prep before paint though.