Owners and police should have the right to shoot these people dead where they stand.
And 20 years in prison is not enough. They should be required to completely replace the vehicle and not just pay for it to be repaired, and I doubt they are doing that. Owners and insurance companies are carrying that expense I am sure.
Rob a bank and steal a few thousand dollars you get at least 10 years in prison. Destroy a $100,000 car, it should be life in prison. Actually I believe stealing or destroying $100,000+ should be a capital crime. And the execution should be public, and viewable via pay per view. That was George Carlin's idea, and it is brilliant.
Carlin on the death penalty:
https://www.youtube.com/watch?v=qDO6HV6xTmI