Weird stuff..received a call from my local Mazda dealer informing me that since I did not have my oil changed by an authorized Mazda center, my engine warranty will not be honored if I have problems. I though this was funny after reading the "Ford Canceled My Warranty" thread. I Had a Toyota before this and changed oil myself regularly and my GF has a Honda and I change the oil in her car and not once has Toyota or Honda told me my warranty would be voided if I didn't use their service. Maybe this is a Mazda/Ford game/policy.