Salle, a far cheaper and more versatile approach is to go to Walmart and buy a $25 or $30 inverter. It plugs into the lighter (or power point in Fords) and provides 120v. You plug the laptop's cord into that. That's how we do it. My inverter is 150 watt and handles the laptop just fine. I've also simultaneously plugged in the charger for my 18v drill battery charger so it will charge while we're on the road. I'd highly recommend this alternative. Then if you change pc's you don't have to buy a new cord.
See another Montana or Mountaineer on the road? Flash lights twice, it might be one of us!
Steve Reigle (pronounced Regal)
Fulltiming since 3/21/03
'03 3295RK
'05 Ford F250 SD Lariat CC SB 6.0L PSD/TS FX4 4x4
Our RV Travels (now Firefox-compatible)