I've stored cars over winter for around 40 years, and I've tried most approaches.
At least in warmer weather, running the engine shouldn't cause condensation issues, but don't half do it. Run it for a long time and use the revs. If you want to turn the rear axle it can be done with the car securely up on axle stands, or just lift the rear and turn the wheels occasionally, which will prevent flat spotting.
Keep a full tank. The only time I've had fuel go off was with a couple of gallons in the tank, and 18 months idle due to a rebuild. It was problematical to resolve. This winter this year was so wet that I put fuel stabiliser in both Morgans.
I've only had the clutch stick once. I've never had flat spots on the tyres.
I'll start my Morgans occasionally. The Roadster takes ages for the thermostat to open...….really ages...…….
I'll be taking the wheels off, and doing a deep clean. I'll be polishing the life out of the paintwork. I'll be conditioning the leather and vacuuming the interior.
Then I'll be looking what else I can do. I serviced them both over winter so the fluids are fresh.
I'll probably clean the Roadster soft top.
