Hmmm
It's like this one with a 12v cigar connector and a 2.1mm plug....
but rated for 120w.....at 12/15/18v outputs....
https://www.jaycar.com.au/60w-regula...aptor/p/MP3478
or maybe something similar here....
http://www.ebay.com/bhp/universal-laptop-car-charger