Suggestions for garage bottom seal for rodents

I installed a garage door a few years ago with my neighbor, albeit wasn't the best install and should have been installed further out in front of the garage floor lip to seal and for rodents. With the uneven garage floor, the gap on the one side is about 2" , we had baby possum get in twice.... Not fun

I bought a bottom threshold but that didn't work , so I temporarily have some rags sealing the low spot. My next idea is get a 3" brush sweep and install on the exterior.

Any other ideas I can do?