Tax Administration and driving a nice classic car in the Netherlands:

To be free of motorcycletax your car has to reach the age of 40 years or older.

That means that only cars of modelyear 1976 and older are road tax free.

There is an additional regulation for cars between 25 and 40 years old. These cars enter into a so-called "quarter rate" pay with a maximum of 120 euros per year. However, this will only apply to cars that run on gasoline. For cars with diesel or LPG engines there's no exception. Just pay the full rate. And don't you dare to drive your car during December, January or February. In that case you will have to pay the full load.