Did you know that there are twelve things that you do no know about car insurance? I took a look at these twelve things as suggested by Insure.com and realized that not only are these twelve things I did not know: they’re actually 12 things that could cost me money. In fact, these 12 things are probably draining my wallet–and your wallet, too!

Insure.com, Inc. (NASDAQ:NSUR) has recently revealed 12 factors that you did not know about your car insurance policy that may be costing you money.

1. You WILL pay for your friend’s bad driving skills

If you let your friend borrow your car and that friend crashes your car you will have to file the claim with your insurance company. Furthermore, you’ll have to pay the deductible. Even though you might get your friend to reimburse you for the deductible, your insurance rates will go up.

2. Stuff that’s In your Car Is Not Covered

Remember the Seinfeld episode where Elaine bought some expensive golf clubs at an auction for Mr. Peterman and she left them in Jerry Seinfeld’s car? And when Jerry had his car worked on by the brother from “Who Loves Raymond” the mechanic started throwing the golf clubs out of the car? Well, guess what? Stuff in your car, even stolen or damaged items like CDs, your iPod, or your cell phone is not covered by your car insurance.

3. You may be entitled to payment for sales tax and registration fees for a new car

If you wreck your car the car insurance company is required to pay sales tax on total loss settlement. Some states require it and some require that sales tax only be paid if you purchase a replace car within a certain time period. In any case, make a request for a sales tax reimbursement no matter where you live.

4. You may be entitled to a diminished value claim in some states

Diminished value means that even though repairs were done to your car after an accident, it’s always going to be worth less: because your car was in an accident. Most states all car insurance companies to use language in your insurance policy that officially “disallows diminished value claims”.

According to Insure.com, there is one way that you may be entitled to a diminished value claim: “If someone else hits you and you make a damage claim on that person’s insurance. That’s called a third-party claim and it’s possible to get diminished value damages as a third party.”

5. Stack Your Insurance Coverage and You’ll Save

If you’re able to, you should “stack” your insurance coverage. Stacking your uninsured/underinsured motorist coverage means that you can collect payment more than once within the same auto policy or across two auto policies. There are two different ways you could stack your insurance coverage:

1. If you own more than one car, you can collect the limit of your uninsured/underinsured policy to cover full payment for damages. [...]