I want to be able to use my laptop in my car (not while driving of course) for my next roadtrip and I know there are adapters that will convert 12v to 110v ac that plugs into the cigarette lighter power but I don't want the thing showing.

Is there any way I power the adapter by connecting it directly to a 12v line? Are there free 12v lines I can use?

 

where do you plan on hiding it? under the seat, in the glovebox, in the trunk? depending on where you plan on doing this, that will determine what wires are available to you... addt'l if you plan to stick the inverter somewhere that doesn't have switched 12v, you can alway run an extension line from the fuse box... just make sure the line is fused before you set your car up in flames...