I looked through the Cedia media guide and did not see a review course for the Designer Exam. I talked with Holly, and Cedia headquarters, and she confirmed there where no pre-requisites for the exam other than a suggested 5 years in the industry. I have field experience, but the engineering portion is what I would worry about.
I long for a better world. One in which a chickens motives will not be questioned when mearly crossing the road.