With most cars the front license plate is in the middle. For an MX-5 or Miata, this is usually placed in the middle of the front bumper using a standard bracket. With some bad luck fitted with a few screws through the bumper ...

I don't think that's a good place. It is of course nice and high, but disrupts the line of the car too much. That is why I chose to fit the license plate in the front opening at the time. It is still clearly visible and hardly disturbs the lines of the front. With the Alfa-Romeo (156/159/169) they chose to place the license plate off center. For me this was an inspiration to see if that would also be possible with the MX.

At the start,  the license plate in the front opening:

First off, to the hardware store to see what they have in store... Surprise! A beam-anchor costing maybe only  2 €uro opens up possibilities. Adding in a left-side tow-brace (yes, left and right are different!). Looked around in my parst-bin for some loose bolts and whatnot.  A bolt, a large washer and a nut with a matching spring washer. And a set of matching bolts to fit the tow hook of course.

Taken the license plate off. This is best! No disturbing elements whatsoever at the front. Unfortunately it is mandatory in the Netherlands to have a plate at the front. Unless I can get a license plate for a motorcycle, but that will be a difficult endeavour considering the four wheels.

Next the beam support is bent into the desired shape with a pair of combination pliers. Origami in steel! Then I made some holes with a steel drill. The holes in the lips at the same distance as those in the old license plate. Saves me from drilling new holes in the plate.

All together:

Adding the tow-hook to the car. I have seen cars withoput a left-tow-hook that did not have threads in alle of the holes.
Next fit the brace and the plate:

And straight from the front:

The license plate is now further forward and it is somewhat more dominant. But I think it's a good addition and a nicer solution than in the middle of the bumper. In which case almost the entire opening remains free for the cooling air.

I am lucky to have a Miata with a smaller (American /18.2) license plate. If you have a "large" European license plate you may have to fit a stiffener behind the plate to keep it straight. This could, for example, be done with a piece of strip steel or an aluminum angle. Maybe you can find another type of beam carrier or a type with longer "lips" so that you have a few more options. I would then place it eccentrically with respect to the mounting point of the bracket so that it sits further to the left and does not protrude (as much) into the front opening.

Good luck!

Update:
I still wasn't quite happy with the location of the licenseplate. So I bought a brace off E-bay. Now the plate is even further to the left.