Except for keeping gas in the tank. My first car sat outside in a backyard for at least 10 years and started right up when I got it from the seller. I know because he was my neighbor and I had lusted after that car (280Z) all through my teens. There was so much rust and crud in the gas tank however that it never really ran right and eventually killed the engine and I had to walk away from it. That was my first lesson about buying cheap used cars... from neighbors. In my defense I was young(ish) and poor and eager to hit the road. But, really, cars can sit a really long time with little or no attention and be just fine.

H