How to charge my laptop in the car?

I have a Lenovo Y500 and it's one of the SLI so it requires a 170w charger. I was wondering if I could just get a cheap adapter that will plug into the car port than allow me to plug my charger in and if that will work? If not, what will work?

You will need a 12v inverter, but it might be hard to find a cheap one that does 170w (200w would be a better idea).

you can get them on amazon, ebay or camping/caravan shops. They plug into the cigarette lighter in the car.

Go to the Levono web site and look for car charger.