How do i mount this?

Why don't you try posting in the "Car Parts Wanted" section. Maybe someone has one lying around for you.

Also, just FYI.....it can be mounted inside the car, but you should use an isolator so no fuel comes inside the car.

Much safer.

I know about my option to run inside with the isolator, but id rather run it on the outside of the car....i cant post anything in the wanted section because im not really sure what mounting cup/pod will actually work with my gauge...thats why i posted the pictures of how it looks on the back for mounting because im not sure what its compatible with