Mileage and years decide which questions come first. Before you sign any service contract, put the same short list to the seller, and get every answer in writing. A verbal answer is hard to check later, so treat it as unconfirmed until it appears on paper.
The mileage line
Ask the odometer reading at which the contract accepts the car, and the reading at which it ends. Ask whether the limit is measured at purchase, at signing, or at the first claim. Ask whether the contract also prints a higher upper limit. The page on printed limits at higher mileage shows what to look for in that wording.
The age line
Ask the age of the car at which the contract accepts it, and the age at which it stops. Ask whether age and mileage are both tested, and whether the earlier one ends the contract. Ask what happens if the car is already past the age line on the day you sign.
The waiting period
A waiting period is the time after purchase before coverage starts. Ask how long it is, whether it is counted in days or in miles, and whether a failure during it is excluded. Ask what the seller does if the car fails inside that window.
Cancellation
Ask how you cancel, in writing or by phone, and to whom. Ask whether any refund is prorated, what is deducted from it, and how long it takes to arrive. Ask whether cancellation ends the contract the same day or at the end of a billing period. Write the answer down.
Transfer
Ask whether the contract can move to a new owner if you sell the car, and what the buyer must do to take it over. Ask whether any charge applies to a transfer, and whether the new owner must meet the same age and mileage limits. Ask whether the contract can move to a different car you buy later.
Get it in writing
Ask for the full contract, not the brochure. Read the sections on covered parts, exclusions, and claim steps against your answers. If a seller will not put an answer in writing, treat that answer as not part of the deal. The scoring method on this site explains in plain steps how the published terms are compared.