Welcome to YC! Glad to have ya aboard. From Vegas huh? I was there from 1998-2007. I was known as MazdaSpeed Dave, lol. I know a few good places and few cool people to talk with while your in Vegas. I think Ed from Acme2 Motorsports might be there, Dana and Jack from Virtual Works, and Dennis from LDL Speed Shop. Just a few heads that are cool.
Far as getting more MPG, check out the mods and owners lounge to see others rides and what they got for increasing more MPG. I just have a air box resonator gone and K&N drop in filter, gets 29.4MPG City (being easy on the pedals and shifting at 2200rpms).
2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille