If its really bad, I take the wheels off and use iron-x, tar-x, pressure washer and a plastic razor for the little specs. It takes time, though.
Deluxe Long Reach Scraper and Plastic Razor Blades
Theres a few places in NY area. Not sure where you are, but I had mine done at Elite Rim Repair in Long Island. Mine are 20" and cost $150 each to fix.
All you want to know about bird droppings...
http://www.autogeekonline.net/forum/hot-topics-frequently-asked-questions/30535-how-long-does-take-bird-dropping-etch-paint.html
http://www.autogeekonline.net/forum/how-articles/23231-how-safely-remove-dried-bird-dropping.html...
Best thing to do is pick up the phone and call them.
Email us or call us toll free at 1-800-869-3011 from 9 am-7:30 pm EST, Monday-Friday, and 8 am – 4 pm on Saturday. International customers call 1-772-286-2701. Se habla espanol!
if you get it from HD or Lowes, you'll have to pay sales tax so depending on where you live, 10% isn't going to make much of a difference. Sales tax in NYC is 8.875% so 10% off is meaningless. I wait for AG sale, get free shipping and no tax and maybe even a free gift. Just got the Flex with...