stevepow said:
Bird Droppings etched my paint right below the passenger side mirror - by the time I got home and washed it off, it appears to have permanently "bubbled" the paint

- I couldn't get it off with any normal or strong cleansers.
Any tips? The car came with a small paint blemish on the trunk lid and the dealer had someone called paint magician or something like that fix it - no sign of anything. Maybe I get those guys to clean it up.
From:
http://www.autoanything.com/car-care/50A25A161A10.aspx
This site has some good solutions about Sap, Bird Poop, leaves etc.
"Bird droppings
Poop happens. It's unavoidable. But what makes things worse is that bird squirt contains some of the most acidic, abrasive, paint-eating substances that ever touch your vehicle. Right after impact, bird squeeze goes to work by eating away clear coat paint layers. If left to its own devices, a heavy splatter leaves a tasty outline and matching blisters or dimples in the paint surface. This repugnant damage is done in 48 hours or less after impact, so time is of the essence.
The solution:
As soon as the you-know-what hits the van, the clock is ticking. The second you pull into your drive at home, spot wash the area with cool water and car wash soap. This should head-off any noticeable damage. If you can't get home in time or have nowhere to wash at home, carrying a mobile kit that includes detailing spray and a paint-safe towel is the ideal stop-gap measure. You'll find carrying a kit like this can be the answer to combating many stain varieties other than droppings. If you were unable to head-off damage, careful paint repair may be in order, with steps as easy as light polish or as costly as professional paint repair. "
My current car is a G35 Sedan, but just the same, in the trunk I keep a micro-fiber cloth, a spay bottle with water and a little white vinager and Meguiar's NXT Quick Detailer. This process comes from the guy that details my car and its seems to work for me - YMMV.
I have to park in a lot for a commuter train so I always come back to some poop on the car. I spay the poop with the water to soften it up and wipe it off with a micro-fiber cloth. Once completely clean, I use the Meguiar's NXT Quick Detailer and a clean micro-fiber cloth. Once at home I have been able to rub it out with a clay bar and wax with a wax pad. Note, it takes time for the blemish to disappear. If you do not regularly wax your car -- good luck! If you wax on a regular basis, its not so bad to remove. I do agree with others, the heat and direct sunlight makes it worse.
Poop happens -- whatcha gonna do!