You can purchase a heater for the car at many stores including Walmart, eBay, Amazon, Walgreens, Sports Authority and Living Direct. The portable ones plug directly into the cigarette socket.
Most car heaters do not exceed 300 watts.
You could have a problem with your thermostat in the car.
Yes, you can do this.
Go to a parts house or a bookstore and purchase a Haynes Manual and they have one that is specific to your car.
Could be heater core is starting to leak
The battery is a 12V car battery.
Portable car heaters can be purchased from a variety of different retailers including car and auto stores (such as Canadian Tire), online through retailers such as Amazon or Ebay, or second-hand from retailers that sell used car parts.
can a 12v lawn mower sealed battery be charged with 12v battery charger use on cars
the heater core could be stopped up, or could be low of antifreeze, or the thermostat could be stuck open
Your car could be low on antifreeze or your heater core could be clogged. With my car, it was Heater matrix clogged with radiator sealant. The workshop cleaned it and it's start working fine!
The 12V air compressor would not be able to lift a car. In fact the average 12V item would only be able to lift about 300 pounds which is not enough to lift a car.