I have about 4100 miles and want to wait until 10k before making a purchase. NE1 have experience good or bad with a California smog legal supercharger unit?

Roadie, Propellerhead
and all around good guy...

2003 530i Sport
2003 Z4 3.0 SMG
1998 528i Sport*
1994 525i*
1992 Toyota 4WD