I photoshoped a few different renditions..

another one took the lines of the hood with the center spine.

and another was just like the one in the pic posted but with the center spine from the roof.

I didnt like either of those. The only other thing I am thinking is just a smooth one. No fins or ridges. Maybe with a small lip on the end of it. Ill try to photoshop something like that and get it up here tonight