Matt,
I personally am not worried about having a full engine cover, as I have an SVT and wouldn't want to cover it up anyway. The one I am personally interested in is the weenie cover.
As for the complete cover, my knowledge is limited when it comes to how much heat that thing would hold in anyway. The reason I reiterated The Great One's point was because of that reason and the fact that heat is a problem with these cars to begin with.
If in fact that it would hold in less than five degrees, I wouldn't worry about it either. However, if this thing were to act as a dutch oven, then we would have a problem with it.
Mike
