I have a 2004 Toyota Corolla with 200,000 mi so don't know if leaving engine idling for 5-8 hrs everyday with AC on bad for the engine especially considering how indestructible are Corolla engines are. I'm planning to live in the car to save money on rent. It's 100+ degrees in the summer. What if I changed the oil every once a month and as long doesn't overheat?
you want to sit in a car for 8hrs a day? Never mind the car, what about your life and your mental health? I think you should work and put a roof over your head.
It will probably be OK, though at 20 years old and 200K miles even a Corolla is getting up there. Make sure your hoses and fan belt are all in good shape and that any radiator fan(s) are working properly. Also keep an eye on your water pump for leaks and wear. If your cooling system fails while idling for hours you could lose the engine when it overheats.
I'd be more concerned about potential dangers to yourself of being in the car for hours with the engine idling. Get yourself a portable battery-operated CO detector that will sound the alarm if carbon monoxide levels rise in the car due to an exhaust leak. A small leak that wouldn't cause problems while the car is moving could be potentially deadly when the engine is idling for hours with the windows closed. I'd also be concerned that someone might break into the car, figuring it would be easy to steal with the engine left running, and what they might do finding you inside it.
Also be aware that some jurisdictions have laws against idling engines for long periods of time and you could be ticketed in such places if a cop notices you.
How about pulling a superlight teardrop camping trailer and sleeping in that? They can be customized with air conditioning and heating, just find a camp site or a parking spot with electricity.
https://hykoutdoors.com/gallery/
Unless you want to live in a 1979 Pontiac Catalina on something like that, I highly suggest not sleeping in your car. My old Pontiac has bench seats and I can relax in when I lie down -the car seat is an inch wider than I am tall. There's enough space in the trunk to put a full size pallet in the trunk, and then some, and the back seats are permanent. When I balanced my Ranger's driveshaft, I took that Pontiac to do it. The trunk was wider than the entire driveshaft is long. My wife and I playfully joke about sleeping in that car if I don't like something she's going to do.
Getting an efficiency, or the politically correct way, studio apartment is light years better than sleeping in your car.
Nash and Rambler cars had optional seats that would fold into a bed, though the feature was intended for weary travelers rather than living in. There were also screens available to put in the windows so you could have fresh air and keep bugs out. (Picture is of a 1951 Nash.)
I actually knew the Rambler had a sear that lies flat! My father-in-law has a 1960 Rambler with that feature. It was pretty nifty car for the time. You also don't need to prime the carburetor in order to start it from cold.
It's a feature that Nash introduced in 1936 when it could be tough for travelers to find decent accommodations on the road.
Who made Nash? AMC? It's a shame they no longer make AMC vehicles. Lee Iacocoa led a hostile takeover of AMC, just because Chrysler wanted the Jeep name. He's the father of the Ford Mustang, but I scorn him for leading that effort.
@justin-shepherd Nash is the predecessor of AMC. The latter was formed when Nash merged with Hudson in 1954. The car companies that became AMC date back to 1902. If you want the gory details of the last days of the company see the book "The Last American CEO" by Jason Vines and Joe Cappy.
By the way, I don't know about you but for me the site here suddenly changed colors after refreshing the page a few minutes ago.
I noticed that as well. You're definitely not alone. Haha.