Dear Mr. Bicyclist,
You don't know me but I was one of the billion or so cars that drove by you today. While I understand the need to blow one's nose, I did want to point out that it is rather disgusting to be riding along on your bike, turn your head, place the pointer finger against your nose and blow your booger into oncoming traffic. I found it very gross and I feel very sorry for the person whose windshield your booger landed on (and exceedingly grateful that it wasn't mine).
However, in the future, when you are preparing to blow your nose the same way again, please make sure my blue Nissan Sentra is not nearby.