I found this product for removing rail dust / rust spots specs on white vehicles in particular and wow does it work. It smells like poo but it really did a great job on my new GMC Denali. Half the time the white is so bright you can't always see the rust specs but you can sure feel them. Yes this is a brand new 2019 manufactured in May 2019 and purchased in July and the hood in particular as well as the roof but not as much, and the back of the tail gate covered in tiny orange specs. It beat trying to clay bar hands down...

After about 3-4 minutes of letting iron x soak




Rail dust rust spots on hood prior to removal







The reaction turns the iron purple as it dissolves