Subpanel placement

I'm looking to add a wall charger for my EV and my main breaker box is full. I've discussed options with some great folks on this forum already and came to the decision to add a subpanel. I don't have space to mount the sub to the left or right of the main and wondering if I can mount it below as shown in the photo. Is there a minimum height it must be mounted at? Any other issues you might foresee in mounting it here? Thanks!