There is no one way to define a classic car and different insurance companies have different approaches to the definition. Cheap auto insurance for classic cars is widely available in the market today and insurers are aware that owners of classic vehicles have a tendency to maintain them very well and their vehicles are not used every single day.
People who own classic cars do not use them often and they take good care of their classic cars; this implies that the cost for classic car insurance will be cheaper than insurance premium for other kinds of vehicles.