You will need to know what type of voltage you are dealing with before you purchase anything, as you could cause serious damage to the equipment or to your car if you buy the wrong inverter. Here is a page with a number of car inverters for sale: http://www.nextag.com/car-dc-to-ac-inverter
Only after testing you. I missed the cut off my a point so I pay for it all myself. They are very strict in their testing and I have heard they are getting worse. Tri-Care will not pay if Medicare will not pay. So I am stuck as are many others.