It has been law in Germany for a couple of years now that the driver of a vehicle has to make sure that the tyres on the car they are driving are suitable for the conditions they are driving in. What this actually means is that if you are driving in winter and snow is forecast, you should have ‘winter’ tyres fitted. Winter tyres, according the German Embassy in London, is any tyre which has the ‘mud and snow’ (M+S) rating. This has opened up an opportunity for rental firms to extract more money from their customers as I found out in January when I had a winter rental from Hertz.