Eh, people worry about this but in my experience with storing vehicles is that it's really not that much of a problem. I put a motorcycle away for 1 year with zero prep. Next year, fired it up, ran the gas through (it seemed a little sluggish but nothing that can't be attributed to placebo), and filled it up fresh. And that's on a carburetor motorcycle with transistorized ignition, which is going to be much more finicky than a modern fuel-injected car with computer-controlled ignition.