[turbo6bar]

Personally, I'd tear off the section from the chimney out (part directly in front of your SUV). Then, start over. You could make the parking pad bigger or add a nice 2 car garage with living space in the second story.

I would NOT add onto the existing structure. It is a lot of work and the results may be a compromise.

You will definitely need to look into city ordinances. You're already close to the pavement.
Best of luck to you,
jurgen