My son parked my car in a parking garage and some rusty water dripped from above--now my car has a rust colored stain on it. Tried washing it and the stain did not come off. Any suggestions?
Ask a good bodyshop to look at this. Worst case if it requires re-painting, your insurance would likely go back at the parking garage for the expense.
Most car parks (here anyway) have a disclaimer so any loss and / or damage whilst on their premises is not their liability. So if you claim on your insurance you will pay at next renewal.
This may not be necessary. Try a mild cutting compound (top brand is marketed as 'T-cut' in Europe but there are others) or failing that try rubbing petrol into the stain. Whichever method you use it is vital that you treat the area with a good quality car wax afterwards.