I know this is an ancient thread, but I have stored too many cars for too many years. (I did 2 tours in germany in the air force) So allow me to share "my" method for storing cars. ;-)
First WD-40 sucks. I have sprayed down bicycles before placing them in long term +3years without daylight only to come back and find RUST. In florida, if you spray rubber seals down with WD, you'll have a nice coat of green fur growing in your door jams later. Any unattended storage longer than 1 year, throw the battery in the TRASH or give it away. Never leave it to die in your car. Something that worked for me my second time storing long term in a storage unit was windows rolled up tight and 2 five gallon buckets filled half way with charcoal placed inside the car. I thought it wouldn't work, but when I returned the charcoal was a powdery mush and the car was dry inside. (I know call me weird) I don't advocate leaving any opening into the car. Little furry creatures can get in the most unbelieveable places. So I bagged up exhaust pipes and intakes. I taped up any openings in the firewall too. Just to be safe, I put out rat and mouse killer on the ground and Moth Balls in the engine compartment. Rodents hate the smell and so do I. Do Not place them inside your car or it will smell like your grandma forever!
Even better is NEVER store a car in SW FLorida EVER. I moved my E-type to a remote place in New Mexico. It was like opening a tomb after 3+ years. I did store the E-type in the air on jack stands unlike the above poster. I did find my rubber joint booties all over the front suspension trashed. The metalastic bushes survived without any issues. SO I think I prefer the strain removed from the torsion bars and rear springs. (you don't "age" the suspension this way) I left the tires on my car and actually reduced the tire pressure to about 15PSI. So far, my expensive Vredsteins have not checked since I have reinflated them. SO what that's worth, whatever. I choose NOT to cover my car because I didn't have time to clean it prior to storing it. It suffered NO changes to the paint. Just lots of water when removing the dust to keep from scratching it later on.
Something someone above missed, Cars with steel blocks and heads, NO COOLANT.
If the car has an aluminum head, Drain and store with straight antifreeze in the system. If you don't you'll see the aluminum sluff off in flakes! Not Good!
As you can see I am talking severe long term stuff here, so no gas ANYWHERE. Dry as a bone. Change engine oil and filter going into storage. And do it again coming out of storage before starting. In florida, I used special spark plugs loaded with dissectant I got from an airplane repair station. Piston aircraft engines leave the factories and overhaul shops with these installed. They gave them to me for nothing.
When I stored the jag in New Mexico, I filled each cylinder to the top with Marvel Mystery oil and then stuck in old spark plugs. Same went for the top end of my motor. I poured a ton of the stuff in the breather on the front of the engine coating the timing chains. I also removed my cam shaft covers and swamped both cams with this mystery fluid. When I exited storage, I removed all the spark plugs and turned the engine over by hand and wicked most of the fluid out of the cylinders with a rope. You should have seen this baby smoke when I finally started it. After cleaning out the oil system, I cranked the car over with no gas until I restored oil pressure, this is critical as everything will be dry.
And my personal #1 MUST DO WHEN STORING IS INSURANCE! DO NOT STORE WITHOUT IT!
I use hagerty for Auto Insurance. Ask them for garage coverage only and go with an agreed value of the car. They will need a photo of the car and need to know where it's stored an if it's under lock and key. I paid around 55bucks a year for around 23K of insurance. That's cheap and I slept better.
You can get really creative storing a car as I've even seen people loosen EVERY hose clamp because it saves the end of the hoses from bulging and looking old. I found it's best to make a list of the stuff you did to the car. Trust me, you'll never remember that big trash bag over your pipes down below until you start it. Ka BOOM!
Enjoy the photos!