I forgot about the Mazda 3... for $20k you could get a very slightly used Mazda3, the base models are about $25k or so. If I had to drive a full sized car, I'd probably go with a Mazda3 hatchback.Mazda 3 or cx5 if you want a little more room.
Timing chain instead of a timing belt so that's one less thing to worry about.
Son is currently commuting from Canton to Tech and is getting 30mpg in a '13 CX5.
Good luck in your search!