So another suggestion, I think this applies to Switzerland and Austria.
I would introduce the possibility that with one registration(1x insurance,1x road tax,1 toll) you can operate several cars that are written to one owner.For each car normally a separate technical inspection every year,the price of registration will be the one for the car that has the most kilowatts and displacement.You could have one small car at home for everyday chores,and one family car for weekends and holidays.