I'm extremely surprised this thread is so long and no one has recommended buying from
www.stubbyantenna.com
Prices start at $13 including shipping and they have by far the largest selection of stubby antenna choices / colors.
Each antenna is rated for reception. So for those of us who want the stubby look but also want good reception, they can find their choice on the site.
Some of the antennas are 'variable length' or 'adjustable length', so you can play with it and lock it in at the length that you find most appealing + gives you the reception you want.
Here are the ones that fit our Z4's:
http://www.stubbyantenna.com/detail1...ey=BMW_Z4_2003
FYI - I don't have any connection at all to the website or owners.