If your only going to be gone for a few months, do it like the New Englander's do in the winter with their "summer" car.
As a quick run down, they tend to fill 'em up with fuel
, add stabalizers to the fuel
, change the oil
, and sometimes put the cars up on blocks. A full tank of fuel minimized condensation
, the fuel stabalizers keep the fuel useable for the months, and changeing the oil removed any acid, or moisture from the engine's oil. The blocks keep the tires from developing a flat spot from sitting for so long. It's typical to put the cars in a covered, protected area. Also, it's typical to add rodent posion to the area around the car.
You can remove the battery
, but it probably won't make a diffrence. After a few months on a concrete floor, a battery will need to be recharge anyway. About the only thing removing the battery would do is prevent a short from burning the car down. Unlikly, but if no one is there to watch it, it's possible.