New car dealers are selling maintenance plans for new vehicles to keep the vehicles coming back for service. In principle, they are good but you need to read the terms carefully. If you have leased the vehicle it may be a good purchase because the plans follow the new vehicle maintenance schedule which always has extended service intervals associated with them. This way you are fulfilling your obligations of the lease. If you purchase the vehicle your maintenance plan should be different. You should plan to get more service work done annually. Oil changes for instance are cheap insurance and adding one more oil change annually will be much more beneficial to the life of the vehicle.
A leased vehicle is under warranty during the maintenance plan so there are not many worries. At the end of the lease you turn in the vehicle. On a purchased vehicle, you want a third party set of eyes looking at your vehicle with respect to potential warranty claims. Most people who purchase new vehicles plan to keep them well past the warranty period so an aggressive early maintenance plan will end up saving you money in costly repairs. Before making a decision on a service plan get some advice. Remember a new vehicle is your second largest purchase (home being the first) so you will want to protect it better to make it last.