The engine, a chassis, the transmission and gearbox, the brakes, the steering, and the frame
There are relatively inexpensive DC to AC converters that you can get for a vehicle that connect into your cigarette lighter. THis is probably the safest way to do this.
Only with considerable difficulty. You're probably better off to trade your car in for one with AC.
Engine- Transmssion, Differential . fuel system, brakes,wheels,Chassis,body.
Usually in front of the radiator, used to cool the freon down.