I know it's not good to let a car sit and not be run for a long period of time, but what if it has sat, for say three or four months? What can happen, and are there things you can do to avoid problems?
I thought that they only problem would be that the battery would die. I don't really think anything major would happened if you left it there. When my husband travels, I try to turn on the car at least once a week.
I had a buddy in school once who let his car sit for most of the semester. Then when he started it up he had rods knocking in his engine, and had to replace the engine.
I don't think letting a car sit for three or four months would do any harm. But a year or longer, and I'd be very careful with it. I certainly wouldn't buy anything that had sat for over a year, without hearing and seeing it run first.
The best option for the car which stands for more then 15 days in garage is, start the ignition for say 5 minutes when you get time, because it will make your battery charging process continuous and the chances of battery discharge will reduce.
There are definite issues with cars that have sat long. It's best to have it towed to a mechanic, as the brakes may need servicing due to rust on the drums and rotors and the calipers and wheel cylinders might be rusty or leaky.