I don't think you need it. This is from the EAS page for the base (non-DSP) Dice unit:
Models Supported:
2003-2007 Z4, including M-Roadster/Coupe
If you want to be sure, send an email to Tom at EAS he will give you an immediate answer. If he helps you, buy the DICE from him. He is a great help on installation details and operating issues.
web site
www.europeanautosource.com
email
tom@europeanautosource.com