Nobody finishes a contract at the desk. You get a stack of pages, a pen, and a finance office that wants the paperwork moving. Before you sign anything, slow down on the blank lines, because a blank line is an open question, and someone else gets to answer it later.
Strike the empty spaces
Go field by field. Check the vehicle identification number, the mileage, the date of sale, the term length, the charge line, the provider name, and the name of the selling agent. If a field is empty, ask for it to be completed before you sign, or draw a line through it so nobody fills it in afterward. Do not accept a verbal assurance to fix it later. Ask for a complete copy that you can read at home.
Match the vehicle to the paperwork
Read the vehicle identification number on the contract against the number on the car itself. Read the mileage against the odometer on the day you sign. A small typo can send a later claim to a file that describes a different vehicle. Ask whether the contract names the car by identification number, year, make, and model, and confirm that all of them match.
Read every initial box as an answer
Forms often ask you to initial beside a line saying you received the terms, understood an exclusion, or accepted a cancellation rule. Initials are not decoration. Before you initial, read the line it sits beside. If you do not understand what you are agreeing to, ask for that section explained in plain words, and ask for the contract's own wording on that point, not a summary from the salesperson.
Get the signed set and keep it
Ask for a fully signed copy of the contract, the terms, and any add-on pages, and confirm that the page count matches what you were handed. Check that the provider name and contact details on the paper match the company you think you are buying from. Photograph every page and store the set in the same place as the vehicle registration and title. You will need it at the first claim, and the person you ask for it then may not be the person who sold it to you.
If you want to read the terms before the form is in front of you, check which providers post a sample contract. The vehicle service contract companies that post a sample contract you can read first page is a useful starting list, and reading a sample at home is a cleaner way to catch blank-line problems than reading a stack at the desk.
Ask these before the pen moves
Ask who issues the contract, who administers claims, where cancellation notices go, and whether the form you are signing is the final version. If the answer to the last question is not an immediate yes, stop and get the final version. Write down the name of the person you spoke with and the time.