I wouldn't worry about the warranty if you do your own oil changes. I worked for Honda for 5 years, and they would clearly state that this was acceptable, and still maintain your warranty. Your only obligation would be to provide proof (if a question of neglect ever arose) that you did this more freqently than the owners manual prescribes. For example, the Hondas required an oil change at least every 7500 miles, or you would void your warranty. So if you did it yourself, you would just need to keep the receipts from the oil and filter, and log the date/miles when you changed it.

I would guess that the Mazda warranty terms are the same. I've never seen a manufacturer require that a car be dealer-serviced.

By the way, I just bought my RX-8 on Tuesday and I'll be picking it up on Saturday! (Red 2004 RX-8 6MT w/ Touring package & appearance packages)

 

If you read the instructions for the PCM flashes, it is mandatory that the car is test driven. There is a specific sequence of speeds and distances that the car is driven in order to take the PCM through validation of the new flash. If your car isn't returned to you with 8-10 extra miles after a new flash you might not have been flashed.

Whenever I drop the car off for service, I ask the service writer to eyeball the car and note that the car has no dings or scratches. Then I have him write it on the service sheet. It's become a joke with the regular service writer. Now when he calls me to tell me the car is ready, he says I can pick the car up today, or I can pick it up tomorrow if I want the dings fixed first.

 

I like his sense of humor. I agree with what was said about how it's ok to do your own oil changes. As long as it is done competently, the warranty is not voided. It's the law. Any of us (most of us, I would guess) who has changed oil could easily prove competence by describing the process step-by-step to anyone who questioned it.

Also, most dealers around here record the mileage when the car is brought in. This may be for their protection, and that's fine with me. A broken headlight or an oil change won't require a test-drive, but beachdog makes a good point about it being necessary for some procedures.