Here's the reply I got from them:
From:
techsupport@autothority.com
Sent: Thursday, June 19, 2008 1:43 PM
Subject: RE: 2006 E90 330i
Hello,
Yes we do, you can expect about 20 hp gain and cost is $795.00.
ECU must be sent in to us for programming and turn around with in 24 hr
Regards,
Min
Turner Motorsports also has a tune listed for the 325i. They too quote 20hp. Check out their website.