Mine sit outside under a soft all-weather cover, so the garage is probably better
My routine for the last 5 years:
- Run the fuel down
- Pick a nice day in October
- Whip wheels off
- Give the underneath/inside arches a good clean/degrease
- Touch up any underseal/paint
- Hit it with BH Atom-Mac and ACF-50
- Take the battery off
- Leave it in gear with the handbrake off
- Cover on
- Come back the following March and enjoy
Cars always start first time, and pretty much look as good as they did before storage.
If your car is a rot box it wouldn't matter what you did to it, it'll still rot. But if it's cared for, it'll survive many winters with the above treatment.
EDIT***This only applied to my 182 track car and my 182 RB. My 182 BG gets the Atom-Mac and ACF-50 treatment but then runs all winter. It'll be its 6th season.