If it's windy, then definitely don't leave any windows cracked open. Instead make sure climate control system is left on 'fresh' and not 'recirc' nor 'off.' (Some cars default to 'recirc' when turned to 'off' or lose vacuum. Check what happens on this car, because this will make a big difference in how hot it gets inside and how fresh it stays.)
Apply a generous helping of leather and vinyl glop to interior. (But be ready to clean windows upon returning.)
Do what you can to block sun from interior.
With an extra jack and a couple of jackstands you could take the weight off the suspension and tires if the ground is firm enough.
Park only on a paved surface to minimize condensation from ground.
I would be most worried about birds, insects, and rodents making a mess and chewing wires. Nine months isn't really that long for the mechanical parts to sit.
Apply a generous helping of leather and vinyl glop to interior. (But be ready to clean windows upon returning.)
Do what you can to block sun from interior.
With an extra jack and a couple of jackstands you could take the weight off the suspension and tires if the ground is firm enough.
Park only on a paved surface to minimize condensation from ground.
I would be most worried about birds, insects, and rodents making a mess and chewing wires. Nine months isn't really that long for the mechanical parts to sit.