Thats actually a pretty cool bg honestly. You have to remember, its not always about how many different things you do, but how well you do the ones you are doing. If that makes sense. If you can pull off a really sweet kit maybe color change, you can afford to leave the bg.
As far as the side skirt...I would continue that big boxy look with a big ole intake to match the bumper. And speaking of the bumper, I would either louver that lower middle portion, or make an opening with mesh. As is sits that area would catch air like crazy. But thats just my opinion. Good work so far.
