Premiums. This insurance is designed to protect you and your car in the event of a hit-and-run accident or collision involving other drivers who may be uninsured or who may not have enough insurance to cover the costs of damage done to you or your property. Get best and cheapest auto insurance in illinois also, find how much coverage do you need with average auto insurance costs by coverage level, company and discounts. Your driving record will have a big impact on your car insurance premiums, as carriers will take your past driving record into consideration when determining rates. Additionally, we rated the best auto insurance companies in illinois based on insurance costs for different drivers, coverage availability, customer service reviews and convenience. Some cities in illinois have cheaper car insurance premiums than others because insurance companies take a driver's zip code into account when calculating their premium, alongside other factors.