[nyalpine90]

i have 2 spots on the roof, i tried alcohol and it didnt work

[ahcow]

Pics would help..

If it is like rust spots, you can clay bar it out.

[nyalpine90]

i posted it a pic, i guess u cant see it

[nyalpine90]

[lbjgh]

Ya, my car has those spots too. I originally thought it was the car rusting until I saw the spots on the plastic bumper cover.

Apparently it is quite common and more obvious on white cars.

[nyalpine90]

i have 2 on the roof , one by sunroof and one by the antenna, it can be remove with a detailing

[ahcow]

You can definitely clay bar that out. Got a bunch of it on my parent's white ML. Kind of odd that you have it on the roof, typically it's on the bumper and side panels.

[BBender]

I think this is poplar buds resin...

[caz681]

Like others, I had the little rust spots appear on the back of my 2011 X3. Having read about them (and taking solace that my plastic bumper couldn't possibly be rusting), I took a clay bar to them. Contrary to reports, they completely resisted all efforts at removal by clay bar. I'm sure that worked for those that said so, but it was completely ineffective for me. As the X3 needed a polishing anyway, I took my Porter Cable orbital polisher and some Adam's machine polish to them and they came right off.

[lbjgh]

Here is a pic of the rust spots on my car...

[k808]

The rust spots in the pic are classic rail dust particles. A clay bar will remove them easily. If you polish your car, they will temporarily disappear, but the rust will come back as the dust is trapped in the pores of the paint and the polish will typically only remove the stain.

[caz681]

Originally Posted by k808

A clay bar will remove them easily. If you polish your car, they will temporarily disappear, but the rust will come back as the dust is trapped in the pores of the paint and the polish will typically only remove the stain.

As I pointed out, my experience is that clay barring did not remove them. Others have had better luck with the clay bar, so it would be more accurate to say that clay barring may remove them. But, it may not.

Keep in mind that the clay bar is only designed to remove surface contaminants, whereas machine polishing can work deeper into the paint (which is why swirl marks and minor scratches can be removed with a machine polisher and not with a clay bar). I suspect that the clay barring I performed did remove the microscopic metal contaminant which was the source of the rust; but, for whatever reason, it was unable to break the bond between the rust particles and the clear coat. Machine polishing took care of that.

Anyway, the bottom line is that it's a more minor problem than it appears, and it is easily resolved with standard paint care methods.