WWGRMD? So, we'll be taking delivery soon of a new CX9, 2.5T.
Here, Mazda Peru offer a 3 year / 100,000 kms warranty. However, brakes and suspension are only covered for 6 months (!). I know, but it's normal here. They won't honour what's left of the warranty if anyone other than their dealer network has serviced it, if you're 500kms over or under any service interval, if anyone other than the dealer has installed any accessory, if anything other than genuine Mazda parts are used (or parts authorised, sold, and fitted by the dealer) (that includes tyres!), "misuse" of the vehicle (which specifically notes exceeding the speed limit..), if there is any evidence of sensors being exposed to water, if anyone other than the dealer has connected any diagnostic equipment or similar, poor quality fuel, impact damage on the underside (very common here for rocks), usage on unsuitable surfaces (most roads here), etc.
In the face of that, that warranty seems pretty worthless (this isn't just a Mazda problem here). They're also widely documented to use the same cheapest oils in all the vehicles, considering the majority here are n/a motors, which use 0w20, I'd imagine they'll use 0w20 in the turbo motor (which should be fed 5w30), they overfill/underfill the oil, reuse filters, etc.
I've personally witnessed complete negligence by a dealer who then refused to even make good the damage caused (500kms after main dealer maintenance, where they were specifically asked to check the brake pads, pads went down to the metal and gouged the rotor whilst out in the highlands. Enterprising mechanic managed to roughly shape some friction material from a truck and rivet it to the pad backing plate to get it back to Lima- the dealer refused to cover anything at all, claimed the driver must have been riding the brakes, then that the caliper was stuck due to being driven off road, also not their fault).
I know early the early 2.5T had issues first with cracked heads, then the valve stem seal issue, but that all seems resolved, and the last couple of years seem to have been reliable.
I average 10k kms per year. When we had our new Mazda 2 10 years ago, they quoted $300 for oil/filter, so I imagine it'll be at least $500 now for the CX9, which is a bit under what my FIL pays on his Range Rover (forgetting parts costs)...
In the face of all that - would you role the dice and DIY service, or just blindly accept and get the dealer to service (here it'd be oil/filter every 6 months/5k kms, so 6 times/at least $3000 at the dealer for the warranty period).