Bruce, you can put it off to the side. I'll bet you could come up with a nice aluminum bracket that goes under the turn signal. And of course, make a dummy round spacer for the other side to match.
Or, you could make it removable and carry it in the car and NEVER mount it. I did drive around with it on once just to get dead bugs on the plate so it looked used. That worked for me.
On my old car, I installed a couple riv-nuts in the body. Then I left 1/4-20 bolts in the plate along with 1/2" nylon spacers and an O-ring on each bolt so I wouldn't lose the hardware. Sorry officer, I left it off after the last car show, please forgive me?
The riv-nuts look best if they are installed prior to paint, like they belong there.