If you’re just running into a store or something, just hit the climate button on the goodbye screen after you hit the Park button and take your foot off the brake. That leaves the climate control on for I think 30 minutes. If you need it on longer, I think I’ve read about folks fooling the car into thinking there’s a person sitting in the driver’s seat with a 10 lb. bag. Then you can essentially leave the car on as though you were sitting in the seat. Not sure that’s very secure, though!