If you have a car that you do not drive for a while here is a very easy way to safe some money:

 In the canton of Vaud you can go to the post office and deposit your license plate for the time you are not driving your car.

Just bring the 'carte grise' and 20 CHF. And inform your insurance company that you are not driving your car for a while.

The post office will send the information automatically to the 'Services des Automobiles'. 

When you would like to use your car again you just go back to the same post office and pick up your car number plates and inform your insurance that you would like your insurance to start again.

You will save, for the time the plates are at the post office, the insurance and the tax for the car. 

Just remember: You are not allowed to drive the car without the license plates as it is not insured for this period!!!