As stated, how hard is it to properly remedy a quarter sized rust spot on a rear quarterpanel? Est. cost at good body shop?

 

Are you talking about right in the very bottom rear corner of the quarter panel? If so I had this problem(almost all hondas do where I come from) and I tried to fix it myself twice and it always came back. You need to go to a body shop or if you have a welder you could do it yourself. I finally went to a body shop and they just put on new metal and a whole lot of undercoating and paint.

But I never saw the price....it was a family friend who did it.