Problem with center caps of my alloy wheels

[DucDirk]

Hey guys,
Sorry for using English, but my German is really too poor... I'm new here on this forum, I'm from Belgium and I'd like to ask you guys some advice with this problem I have:
Early this spring I bought a Z4 2.0 (pictures can be found in the gallery), and shortly after I replaced the standard 16 inch wheels by 18 inch wheels Zilliom Z10. The center caps (you know those things you see in the middle of the wheel) of these alloy wheels however apppeared to be absolutely ugly, so now I'm looking for an alternative by which I can replace them. For the moment I put Rial-center caps in the middle, on which I glued the BMW-logo, but that's only a temporary solution: I already lost one of the logo's (front left wheel : see gallery).Can anyone help me with this ???
The problem is to find center caps that fit exactly on Zilliom Z10-wheels, preferabley with the BMW-logo.I'd be very obliged !
Greetzzzz,
DucDirk