Poor boys world bird sh#t remover or honestly any quick detailer. If I were you, I would just get a really good microfiber towel and some bird sh#t remover and throw it in your car. Bird sh#t remover is just a hyper-concentrated quick detailer. Just let it soak for a minute or two and it should wipe right off.
2009 E90 328i Monaco Blue
premium/idrive/convience/logic-7/cold weather/ xenons/ saddle brown interior