See that they are listed in the Better Business Bureau or Web Assured, and they have years of experience.
Some might say just go for another used car, but as you probably know, your next used car might break as well.
Some dealers of used cars can already include a guarantee in the used car package, while others can not.
An item that does not read well is never published on a website of high level.
Also, if your plan is to sell the car before the expiry of the extended warranty, you can bet it will be a great selling point and it will add value to the car.
If you are looking to buy a new or used copier but are concerned about the quality of local service, a copier warranty is the only way to ensure peace of mind with your purchase.