How to prep my M3 for proper long-term storage?

[ArtiM3]

My car sits in the garage for more than 2 years. Only driving during summer. Covered maybe 1000miles since parked. I got nearly empty tank. Just enough fuel to start the car and reach nearby Petrol station. I’m always removing battery and keeping it at home. I got indoor car cover so my M don’t collect any dust. Other than that nothing else. Car always starts without any problems.

[timmo]

If you're concerned about rodents, it might not be a bad idea to plug the exhaust pipes and intake. Be sure to put a big reminder on your steering wheel or something so you don't start the car with these things plugged.

Ha, I left a couple plastic bags plugging up my exhaust and started my car up after 1.5 years, man it ran rough. I was worried about it being bad gas even though it was stabilized, then remembered the bags and pulled them out. Purred like a kitten after that

[turbosig]

Ctek battery tender first and foremost. I have a garage queen which sits all winter and fall. I use a tender and make sure the air in the tires is a tad over inflated. Other than that, that’s all she wrote.

[eljay]

Here's my winter storage procedure checklist that I picked up somewhere and edited slightly:

Winter Storage Procedure

* Put in fresh oil/filter
* Fill the gas with fresh fuel from a top quality station using high octane (no alcohol if you can help it). This reduces the amount of fuel tank wall space that would enable condensation to accumulate during the changing environment temperatures. Add a gas preservative such as Stabil and run the engine for a few minutes, so it can be distributed throughout the fuel system.
* Put plenty of air in the tires (over inflate slightly). 5 to 15 pounds should be enough.
* Make sure the car is thoroughly washed, including the underbody.
* Wash and wax your car right before storing it.
* Store the car only when it is dry.
* Make sure the car has had a good run on the highway before storing it. By getting your car up to operating temperature it helps to burn off contaminants in the oil and it also gets rid of moisture in the crankcase and the exhaust system.
* To stop moisture from getting under the car put a couple layers of plastic sheeting under the entire car and several feet either side/ends. This plastic is cheap and a good vapor barrier.
* Close all the windows and put the system on max a/c to close the outside vent. If the garage is heated, then the window can be left open a small crack to allow air circulation.
* Put a large bag of desiccant gel inside the car. This absorbs excess moisture in the air. Put them in a pie tin on the floor of the car. You can also place an open box of Baking Soda on the floor of the car to absorb moisture. The Passenger Side floor works fine.
* Treat all rubber with a good rubber cleaner/conditioner. Clean your interior and vacuum it out, use leather cleaner/conditioner and vinyl cleaner/conditioner as required. Do NOT use water on the carpets/seats right before storage, mold and mildew will follow. Do NOT treat inside surfaces with Armor-All (or similar) products before storing your car. They contain a lot of water and chemicals that can encourage mildew and mold. You may get a musty spell concentrated over the winter.
* Connect a quality trickle charger to the car (like CTek etc.). Connect it to the terminals in the engine bay, not onto the battery itself (this ensures the battery control module can regulate voltage to the various electronic components.
* If storing the car on the wheels, place cardboard or old carpet pieces under the tire to separate from the cold concrete. If you put the car on jack stands, use them under the suspension so all the bushings and springs are the way they are supposed to be, and not drooping down. Drooping from the weight of the wheels etc is hard on the suspension, and exposes parts to rust that normally are hidden.
* If the car is manual, leave it in gear. Use wheel blocks to prevent it from rolling.
* If the car is stored on its wheels, it may be helpful to roll the car slightly once a month.
* Never set the parking brake. The brake shoes or pads could stick to the drums or rotors or the cables could rust or freeze up during storage. Use wheel blocks.
* Put steel wool or rolled up scotch-brite pads in the tailpipes and the air intake inlets.
* IMPORTANT!! It is far better to let your car sit for four or five months without starting it, than to start it once a week, or once a month and let it sit for 10 minutes. NEVER start your car unless you plan on driving it on the highway for at least 1/2 hour and get it to full operating temp. Doing otherwise will just load the engine and exhaust with moisture to start rust etc.
* Place a sticky note on the steering wheel or dash with the words: "Remove steel wool from exhaust and intake before starting!"
* Cover it using quality fitted cover
* OPTIONAL: whisper to it, or play sounds of M3 GTR going around Nurburgring from YouTube until the car is peacefully asleep and comfortable.