INDIANAPOLIS (CONSUMER REPORTS) — The next time you rent a car, you’ll likely get the same question as the last time: Should you buy rental car insurance? You might think your credit card or auto insurance covers you, but that’s not the whole story. Consumer Reports reveals the crucial questions to ask before your next rental.

Both auto insurance and credit cards can have significant limitations regarding rental cars, including what kinds of vehicles they cover, for how long, and in what countries.

Rental car insurance can be expensive, sometimes an extra 50 bucks per day. When does adding it to the rental make sense?

If you only have liability insurance on your car, you’ll need to get a separate policy for the car
rental in case there’s damage to it in the event of a crash.

Here are some guidelines to help you decide if extra coverage is right for you:

• Is the rental car fancier than your car? Some credit card rental insurance and personal auto policies won’t cover certain car types or classes, like large sport utility vehicles or luxury cars.
• Are you renting in a foreign country? Allstate, Geico, Farmers, State Farm, and Progressive say that your auto insurance coverage extends only to car rentals in the U.S and Canada. The same goes for rental insurance offered by most credit card companies.
• Finally, if you’re renting an RV, a cargo van, or a moving truck, these vehicles are usually not covered under standard auto or credit card insurance policies.

And if you decide to add extra insurance, consider adding up to three types –

• Collision Damage Waiver, which covers damage to the car in case of a wreck.
• Loss Damage Waiver, which protects you from theft and damage to the car.
• Liability coverage covers you if you are found legally responsible for property damage or for injuring someone while driving the rental.

Terms might be slightly different depending on the rental car agency. If you’re renting a car for work, check with your employer to understand what’s covered and what’s not since your personal insurance and credit cards likely won’t provide any insurance for these types of rentals.