Collision coverage and comprehensive coverage are two types of auto insurance that cover physical damage to your vehicle. They are normally purchased in addition to mandatory insurance which usually cover only liability or uninsured motorists depending on the state.

Insurance companies pay close attention to two factors when determining your premium rates for collision coverage: claim frequency and their loss per claim. A low claim frequency means a lower premium rate and the same applies to loss per claim. If you own are 4-door car, or are planning to buy one, here are a few things to keep in mind while purchasing collision coverage for your vehicle.

Only very large 4-door cars have a relative claim frequency of less than the average 100 (where 100 represents the relative claim frequency for cars of all sizes and models). In other words, all 4-door cars, except very large ones, file more claims than average, ranging from 108 to 111. Very large 4-door cars have a relative claim frequency comparable to 2-door micro cars at a score of 72. This means that it costs more, on average, to insure a 4-door, with the exception of very large ones, than other types of cars.

The relative losses per claim for most 4-door cars also hover just above the average figure of 100 (here again very large 4-door cars are the exception with a score of 81). The relative losses per claim for 4-door cars range from 100 to 117. This means collision cover for 4-door cars cost slightly more than average.

Collision coverage for mini 4-door cars such as the Kia Rio costs an average $428 as of December 2013. A small 4-door such as a Volkswagen Golf will cost you $417 on average whereas a Volkswagen Jetta, which is classified a medium sized car, will cost $426. Collision cover for a large 4-door such as Dodge Charger will cost $553.