I used to do all my service myself until I started to buy new vehicles instead of used vehicles.
I have found that using the approved dealership can cost a bit more, but it pays off in the long run. They are much more willing to stand behind the product than if you get the vehicle serviced elsewhere or do it yourself. I have even found thatif the dealer relationship is good, it does not matter if you have aftermarket accessories installed as the dealer will go to bat for you with the Company. For me, my last few cars have all been dealer serviced and I continue to do so. Makes getting warranty repairs so much easier.
Just my 2 cents worth.