Thanks for all the replies. There are two images because I took two different pictures because I wasn't sure which would be better. The top image is the one I took while standing back from the car and trying to keep the lens at about the center of the side of the car.
I am going to be putting in a block on the smaller upper grilles I wanted to see which would be better though. I was going to take the easy route and put it in behind cause I can use the screws that hold the plastic mesh thingamajigs in
I'll put it on the outside though based on what aerohead said.
I think I'll probably just leave the spoiler as is for now. I considered doing ABA testing but since I lack a scangauge and because the spoiler houses my third brake light it's kind of an involved process to remove it and having the holes it leaves behind to let water leak into the trunk isn't too fun either.
Thanks for the advice on the wheel covers too. I was wondering because the way my wheels are it would be easier to mount covers to the back side rather than the front.
I wonder if having covers on the front and back would make even more of a difference? That way the air behind the tire would be smoothed out as well?
I'll have to see if I can find a VX next time I'm at the junkyard and take a look.