Everyone has their own opinions and, hopefully, others on here with chime in, but here's mine...
When I finance a new car, I finance as little as possible. This means no add on's, no additions, etc. That alleviates the need for GAP insurance to a great degree.
I then pay it down as quickly as I can within reason. Even just a few extra bucks each month. If you can afford all these add on's, remove them and put the funds toward paying down the car loan. When the car is nearing its end of the bumper to bumper warranty I then decide if it's worth purchasing an extended warranty. At that time, you ask yourself...
- how reliable has the car been
- how much longer do I plan to keep the vehicle
- how costly are repairs
Yes, the warranty does cost more at that point, but much less than the cost of financing it for those first three years while you have no use for it and there's always the strong possibility that you won't even own it past the bumper to bumper period. (wants, needs, and wrecks happen)
I do believe that a warranty is a valuable thing to have for this particular type of vehicle, but a good one came with the car. I see no reason to pre-purchase AND finance one now that you may not use/need. The key to this all is to not finance anything more than you need at any given time.
I treat cash purchases differently.
FWIW, I have been a car salesman, have a degree in finance, have a wife who works at a dealership, and have bought/sold many cars.