comments:
An exhaust fan? You mean a fan you can just leave in your window to help cool the car? They've had ones that are solar powered (like these: https://www.amazon.com/Solar-Powered-Car-Exhaust-Fan/dp/B0GTMYY4KV ) for as long as I can recall, but I don't know how good they are. Best option might be to learn to open the car doors in such a way that the hot air built up inside is forced out. Open rear passenger-side door, leave it open, and open/close the driver's side door with some force to help cycle cooler air in. Also look to see if the AC might need recharging. Ultimately, it's a metal box. It's going to get hot. Nothing is going to keep it cool outside of shade and active cooling (like air conditioner). At a minimum, just sitting and not having AC running, it's going to be as hot & humid as the surrounding air. At worst, it's 1 1/2 ton solar cooker on wheels.