So, title says all, As I was washing my car by hand a few days ago, I stumbled upon a scratch that has rust on it, It's about the size of a quarter. It's on the roof of the vehicle. Close to the windshield. I'll post a picture up soon....

I was wondering what should I do?????... I'm planning on getting a paint-touch-up kit from Volvo soon. Is there anything else I should get/do??...

 

Sand off as much rust as you can. Wire brush etc. (Use masking to avoid sanding good paint.
Apply rust killers per instructions.
Apply rust proof primer.
Touch up paint
Clear coat

 

You could get one of those little stiff fiberglass brushes (looks like a pen actually) that are made precisely for cleaning/sanding out such scratches prior to touching up with paint.

Search Amazon for "PrepPen Adjustable Sanding Pen", they run $8.