An auto DC adapter has a cigarette lighter input plug on one end that is plugged into the cigarette lighter receptacle and on the other a special output connector that is plugged into the laptop's power receptacle. Although recent P4 laptops have higher and higher power requirements, auto batteries have the capacity to supply the necessary output for the PC.

SAMSUNG
    Samsung X50 WVM 2000

    Samsung NP Series
        NP-30, NP-Q1, NP-Q30 Plus, 
        NP-R50, NP-X20, NP-X60 

    Samsung Sens Series
        Sens 690, Sens 900, Sens 950, Sens V10