Here's my DIY license plate bracket. It does remove the plate light. And I guess I can put a smaller one later.
After some searching in Home Depot, I found this.
I was going to put them together like this so the angle of the plate can be adjusted. One end would attach to the bike and the other to the plate.
After looking at the setup, I saw I could get by with using one bracket. So I drill holes on the plate side to mount it underneath the viffer. Then I bent the sides slightly to make flaps. Those flaps are used to mount the plate on.
Then I drilled holes on the bent flaps on the bracket, and on the plate. Those other little holes on the plate were from the previous owner.
Then I painted it black and bolted everything in place.
Spent around $4 and used paint and spare screw I already had. Enjoy!