A new 2006 law shifts responsibility for having snow tires on the car entirely to the operator. Most rental car companies do not equip their cars with snow tires by default. Extra charges of up to â‚¬15/day apply. If you do not specifically ask for snow tires before you pay for the rental, you will be in a difficult position to negotiate a fair price.
If you do not have snow tires and have an accident with the car in bad weather, insurance coverage can be declined. You can be fined by police if you are stopped driving on snowy roads.
So, if you are planning a trip to Germany or Austria this winter and will use a rental a car, make sure that you get snow tires. If you have already booked a rental car, follow up with the rental agency and make sure that you get snow tires. Request a confirmation in writing.
See this report in German for additional information.