During my last visit to NY, I noticed that several cabs displayed painted flower designs on their bonnets. They looked beautiful. They made the iconic yellow cabs look even more pretty and eye catching. The design is so simple that it does not add a lot of complexity to the picture, and is very pleasing to the eye. They look beautiful especially when viewed from above (for which there are plenty of opportunities).
I discovered that school kids created the paintings, and NY city printed them on weatherproof adhesive sheets and supplied them to willing cabbies to display it. Lot of this art is created by kids in hospitals. It is aimed as an artistic outlet for the children. Flowers were chosen as the subject because they are "one universal symbol of hope, beauty, life, joy and inspiration".
It sure is a sight to behold.