You often look at the features and read what is covered and what is missing in the plan.
This way, the buyer knows what happens when a service is needed. In this way, the contract holder would know where to ask for repairs and that they must apply the necessary services.
Moreover, the plan is registered with the vehicle and as such is transferable to the new owner should be sold the car before maturity of the plan.
You will have installed new programs as well as get past people repaired.
Also find out if your car is under warranty. If you have a new car warranty then any and all items that are covered under warranty must be borne by the dealer.
Buying a car is a significant financial investment, and you should do everything you can to remain pragmatic.