A few more info on that subject. It takes 3 to 4 minutes to start the vehicle and you can drive about 150 miles without refill (wood or coal). I haven't found anything on speed but as soon as I do I'll modify this.
Here is a picture of a true one. Thanks the Swiss, what would we do without them.
Ok I go for the last mod. I found that guy driving one nowadays (2nd picture with the Peugeot 504). it drives 300km (more or less 200 miles) with 60kg of wood and his car got a speeding ticket for driving above 90km/h.