I did this to my Astra, but I cannot prove I save fuel. My feeling is I did...The wind noise seems also to be lowered. If you have a board computer and you will do such thing, maybe you can see a difference.
the lower side panels I placed because, you know, in that area is a kind of "wind trap". The central grill block is ugly, but the "no badge" grill I've rework was waved...
