I made one out of hard plastic plumbing pipe I got at the hardware store for .50cents.
It's been on Mbb41's car for over 1 year now with no problems.
It was similar to this, I just cut off the end (length needed), drilled a hole in the middle the
size of the ball and cut a narrow line from the end to the hole so it could slide on. It was amazing,
it snapped onto the ball like it was factory.