I used Forever black. It is miles better than the Renovo i had tried previously. 1, being that it isn't a horrible runny liquid you have to brush on and 2. It dyes the roof blacker and leaves a much more consistant finish that lasts longer.
http://www.amazon.com/Forever-Car-Care-Products-FB813/dp/B001879CUS
Protected with Fabsil. Excellent stuff that goes on easily and seals & protects the roof. Water just beads off after it has dried.