A lot of excellent tips!
About 10 years ago I owned a 1971 280se /3.5. It had just a few rust spots when I put it in a garage for about 12 months planning to start an engine restauration afterwards. When I got back to the car the complete floor had rusted away.
Here in Norway the humidity can be above 90% from october to march. Fore this reason I bought a Car Coon last year for storage. Last winter I managed to get the humidity down to about 70% inside the tent. If I increase the heat I belive a 50% figure should be possible.
I think the most important thing is to make sure the car is air dried before storage.
Per G. Birkeland
69 280 sl aut 834
Norway