Removing Rub Marks

[Road Geezer]

We just got back from a 10.5k trip across country. Somewhere along the way I picked up a couple long rub marks on the exterior aluminum siding. Whatever rubbed against the side didn't crease the aluminum, nor did it penetrate the plastic coating. It was almost as if a bicycle handle grip created the marks.

I've removed the residue from whatever rubbed my side, but I'm left with shallow scratches in the plastic coating, kinda like would be made by an abrasive stick. I tried Maguire's touch up car polish (non abrasive) and it helped a little, but did nothing to remove the scratches. I then tried wet sanding a small area with a 12,000--yes, 12,000, not 1,200--grit furniture finishing pad and I can tell that with enough rubbing I will eventually polish out the scratches. I just don't know if I'll cut thru the plastic, so I'm looking for any advice on alternatives before I expend all the elbow grease I'll have to with wet sanding.

Has anyone out there had a similar problem and found a solution? Ideally, I'd like some sort of plastic clear coat patch that would fill in the scratches without having to polish.

Appreciate your help,

Paul