I have this problem myself, I blame my constant reading of Autoblog and the like. Seems there's always something newer and better than what you have, be it car, cellphone, tool, etc. Honestly, I was ridiculously close to picking up a Genesis Coupe just a few weeks ago, but then the sensible part of my brain reminded me that I've only owned this brand new car of mine for about 6 months and I'd be an idiot to even think about dumping it now. I kept my last car for 5 years (MINI Cooper S. Most unreliable thing I've ever owned. Fun as hell when it wasn't broken, though!), so I don't see myself getting rid of the stang anytime soon. Not to say it isn't fun to look, though!
2013 V6 Premium A6 - Airaid CAI, Bama 93H Tune, FRPP 3.55 gears, Dynomax Catback