Want to make my car inaperable (theft)

I'm planning on flying out of Seattle in a few weeks. I am going to find a place to store the car, offsite or at the airport. Seatac is notorious for auto theft.

I want to do something that makes my car not start. Or better yet, so they can't open it with a computer scanner thing.

If I park it, dig down and unhook my 12V battery, will that make it so it wont start? If so, will I have anything to worry about coming home 5 days later?

Any other way to disable a car so no one can steal it?

Thank you,
ebm