Last year, my
grill block on the Prius worked pretty good. However, on a windy day towards spring I did have one of the thumb screws back off and I ended up loosing it and kinking the coroplast. So, I thought up a new way to mount the grill block that I think makes a lot of sense and is incredibly easy to do.
I started out with some left over 1x4s I had laying around. These scraps worked perfectly for the project. I drilled a clearance hole for a 2.5" wood screw in two of the blocks and a pilot hole in the other two.
I then drilled a countersink in the blocks with the clearance hole so the stainless deck screw I was going to use would sit below flush.
Next, I stuck the block with the pilot hole behind the grill and screwed them together with the block with the clearance hole on the outside of the grill.
And then I mounted the other. Now, the blocks provide us a place to screw the grill block to. It also positions the grill block much more flush with the bumper instead of being inset like most grills are. This should improve aero a little bit. Also, its very easy to compensate for different grill depths by using different thickness outer blocks.
Lastly, I held my grill block up to the blocks, drilled holes, and used button head screws and fender washers to hold it on. It is much more sturdy than my last method of attaching the grill block and it sits almost as flush. A little tweaking will fix that though.