People buy service contracts to close a worry. The worry is usually a repair bill for a part they cannot afford, on a car they cannot easily replace. That worry is real, but it is not a reason by itself. A contract only makes sense when it closes a gap you would actually fall into. Start by finding the gap.
Check what already runs on the car
Look in the owner's guide and in the paperwork from the purchase for any manufacturer warranty still running. Note the basic and powertrain coverage periods, and whether either has already ended. Find out which systems the existing warranty covers and which it does not. The overlap is where a contract can be pure duplication, and you should not pay twice for the same protection.
List the repairs that would hurt
Write down the systems that would cause you the most trouble if they failed: the engine, the transmission, the electrical system, the air conditioning, the steering, or anything else specific to your car. For each one, ask whether a repair would strain your budget, your work, or your family. A part that would be a minor inconvenience does not justify the same urgency as a part that would leave you without a car for weeks.
Signs that a real gap exists
A gap is real when the factory coverage has ended or will end soon, the car is one you depend on for work or for getting children to school, and you do not have savings set aside for a large unexpected repair. It also becomes more real when the car has a history of expensive faults that you know about.
Signs that the gap may not exist
A gap is weak when the car is young, the factory coverage still has a long run left, and you could pay a repair bill from money you already have. It is also weak when the contract would largely repeat what the warranty already covers. In that case, the contract is paying for a feeling rather than a risk.
What to do with the answer
If you find a real gap, compare contracts on the terms that matter for that gap, using the published tables on this site and the sample contracts some providers post. If you do not find one, the honest answer may be to skip the contract and keep the money for repairs you pay yourself.