Most rental car companies will try and get you to buy additional insurance, like loss damage waivers or personal effects coverage, but this can set you back $20 to $40 more per day. If you have your own car insurance or an AAA membership, you probably don't need to purchase this additional insurance, but make sure you double check before skipping out on it entirely. Also, many credit cards offer free rental car insurance when yo use the card to pay for your rental, so check out this article to learn more about which cards offer this service.