any methods to get rid of stains on the exterior?
 

There are brownish spots on the exterior of my white Mazda .... it's only a few months old.

Couldn't get rid of the stains when i washed my car! Previously there were stains but i could clean them off! Is there anyway I can get rid of them ?

Thanks.

If they have permeated through the clear coat, you probably will not get rid of them. I would try clay bar, if that doesn't help then try checking with a professional detailer.

He's right professional detailers use a clay bar to remove stubborn car stains.