The people who are selling these shirts are... well... I think we can all think of a term that starts with 'A' and ends with 'holes'.
Unbelievable. Freedom of speech allows these ("D" ...ends with "its") the right to express their ("D" ends with "ss") opinion, no matter how misguided or wrong it is.
That said, they put that sticker on their car, and as if by magic, my keys might just have dust on them the same color as their paintjobs! Amazing how that works, isn't it?
And if they practice what they preach, can you IMAGINE how the media would CONDEMN some d*p***t who actually hits and kills a cyclist with this bumper sticker on his car? (if, y'know, they don't drive off like cowards...)