Carmakers have offered free maintenance plans on new cars for years, but nowadays you may be able to land a deal for a free maintenance plan on used cars as well.

Getting a free maintanance plan with your used car can save money, but as always you need to me alert and ask an auto tech the proper questions. Here are just three auto service questions to ask before accepting any maintenance service for pre owned vehicles.

1. What kind of maintenance is included?

Everyone offers different deals, and some try to be sly by playing on your expectations. Basically go over any auto service questions you’d ask a mechanic and see what is covered. A program can offer several years of full servicing, or they may just include one free oil change. Why buy a used car if you can’t be protected from unexpected hiccups? Sure, used vehicles today are safer and have fewer problems than the used cars of yesteryear, but when you save that much money on a used car you don’t want to spend it on maintaining the car anyway. Might as well have gotten a new one in the first place.

2. What is excluded?

This is different from asking what is included. Common needs such as new tires, windshield wipers, or brakes typically aren’t included in these plans, and questions to ask a mechanic or dealer is what sort of quirks the car might have that would necessitate better coverage.

Also ask what parts of your maintenance plan aren’t covered. The plan may cover the labor to replace an air filter or oil, but it may not pay for the actual product. These little costs can stack up, especially depending on how well the used car has been restored.

Tip: A certified pre-owned car should meet a manufacturer’s factory standards and therefore tend to have guarantees similar to new-car warranties to cover defects. If you’re buying a certified pre-owned, read your warranty policy carefully in case you don’t get that guarantee and need a free maintenance plan after all

3. Are there conditions for me to meet?

It’s reasonable to require work done under a free maintenance plan to be done at a specific dealership or shop, but there are other possible snags to watch out for as well. A dealer may want you to get ALL servicing done at the dealership, even the ones not covered in your free plan. The free maintenance plan may also come tacked on to an extended warranty or financing, meaning you have to commit to other deals before you can take advantage of this one. It helps if financing or extended warranties are things you want anyway, but still be careful about seeing a free maintenance plan as a deal when it’s not.

Always read your contract carefully before signing and get all of your auto service questions answered. You know this is a significant purchase, so you know to be careful, just don’t forget the hidden catches that make car dealing so infamously tricky.