Start with the drive you actually make, not the one the brochure assumes. A long highway commute puts steady, warm miles on the engine, drivetrain, and tires. A car that crawls through traffic every morning spends a different kind of time running, with the engine idling and the cooling system working hard in heat. Both are real wear, and they show up on different parts, so a contract that suits a short city errand car may not suit a commuter.
Check the mileage lines first
Most contracts set a mileage ceiling at purchase and another over the life of the term. Find the exact words for both. If your car is already close to the purchase ceiling, or your commute will carry it past the term ceiling before the contract ends, the contract may not fit even if the price looks right. The published mileage figures for each company are in this site's comparison table, and the list of providers that take high-mileage cars, with maximum vehicle age is a useful place to see how the age and mileage limits relate.
Ask how miles are counted
Ask how the contract measures use. Most contracts go by the odometer reading. Ask what happens if the odometer is replaced, how a disputed reading is settled at claim time, and whether the contract wants the reading recorded at each service visit. Keep a written log of every service visit with the odometer reading beside it, because that log is what you will show if the numbers are questioned.
Ask whether idling counts for anything
Many contracts measure miles, not engine hours, which means traffic idling may count for nothing on paper. That does not make the idling harmless. It means the contract may not reflect that wear at all. Ask the company whether any part of the contract is written around engine hours or heavy-use driving, and get the answer in writing rather than in a sales conversation.
Match the car to the commute
Write down the miles you drive in a typical week, the share that is highway and the share that is stop-and-go, and how many years you plan to keep the car. Compare those figures with the contract's term, its mileage limits, and its maximum vehicle age. The gap between your real use and the contract's limits tells you more than any headline or sticker on the windshield.