I'd say leave it on too. I remember some time ago someone with an 8G posted a pic of their engine bay with a cover from a Diamante. Can't remember if it was a 6G72 or 4G64, but it looked pretty good. I always thought about doing it too.
Edit: Must have been a 6G72 seeing that the Diamante is a 6G74.
Here is a pic of the cover on a Diamante:
http://www.familycar.com/RoadTests/M...ges/Engine.jpg