QUESTION:  
A little less than 10% of all people say they have either had or nearly had a car accident because of this; what is it?

 
It’s a bodily function 

ANSWER:
A little less than 10% of all people say they have either had a car accident or nearly had one because they sneezed!      

Congratulations to Bruce Crabtree of Richmond for being the first to answer the Impossible Question correctly!