* Insurance companies consider many factors: These include the driver's age, driving history (accidents, tickets), location, the car's safety features, the car's value, the car's theft rate, and repair costs.
* Similar safety and repair costs: Many modern station wagons and sedans share similar platforms, engines, and safety features, leading to similar repair costs and safety ratings. This means the difference in insurance premiums might be minimal due to these factors being largely equivalent.
* Potential for higher repair costs (rare): In *some* cases, specialized parts for a station wagon's longer body might be slightly more expensive to replace than those for a sedan, *potentially* leading to a higher insurance premium. This is not always the case and is highly dependent on the specific models being compared.
* Perceived risk: While not a major factor, some insurers might subconsciously (or through actuarial data specific to their customer base) associate certain body styles with certain types of driving. This is hard to measure objectively.
In short: To determine which is cheaper to insure, you need to get quotes from multiple insurance companies for specific makes, models, and years of both station wagons and sedans. The body style alone won't predict the price difference.
