I can't figure this out

[XSFDetail]

http://tapatalk.com/mu/461cf53b-f052-fa83.jpg
I am having customers come in all the time telling me their vehicles are rusting. This is not rust but something being thrown up off the road. Rail dust was my initial thought but this is always concentrated on the bottom of vehicles.
Does anyone else have any answers?

[Ted S.]

Looks like iron fillaments...

Iron X?

I've never tried Iron X, but this looks to be a case for it.

[Pockets@PoorboysWorld]

Fresh tar oil? Have they all been recent?

[Subieski]

Could be from the brakes of the car, or indutrial fallout getting kicked up when it rains. My wifes car gets that all the time on the lower panels and teh back bumper and trunk surfaces (where the wake of the car starts) Iron x or a lot of elbow grease and a clay bar should take that off.

[rwright]

Fresh tar oil? Have they all been recent?

Great observation. :xyxthumbs:

[XSFDetail]

I actually have to deal with some in the dead of winter, there is tar too on this one, but nothing is fresh, I am sure it is coming off the road the way it presents itself only on the lower panels and rear of the vehicles, I have not tried iron x, but I may be needing to get me some. This is getting real old real fast, and I am normally a patient man! Thanks for the help guys!!!