Here's a funny story about Subaru's Service dept.:
If you went 2 years on dino oil without a single oil change, do you think Subaru would try to void your warranty? I suspect they wouldn't be too keen on your maintenance habits.
Ironically, that's exactly what the dealership did to the new 2004 WRX that I just bought. It's been on their lot since 8/2003 and never sold. I bought it new 8/2005 with 900mi on it. I checked my oil level on the 4th day I had the car and it was a quart low. I took it in and asked for oil change records, and, surprise, they hadn't done any oil changes. IN 2 YEARS! I asked the tech what she thought about the manual's recommended oil change schedule and she said it's absolutely necessary to change the oil every 3 months. Certainly good for their revenue, anyways. She also said that I was not covered if I put in Synthetic oil. She couldn't explain why the level was a quart low- just saying that since my car had about 1000 miles on it that it wasn't totally surprising that it had consumed some oil. I assume that it consumed oil because quick, short test driving is not easy on the oil.
It is pathetic that the same people who try to void the warranties of enthusiasts who mod their cars to improve them would be so basically imcompetent with maintenance. I know this story probably reflects more on the competence of that particular dealership than that of all subaru techs, but seriously...2 years and nobody noticed. I think I'll have any warranty service performed elsewhere.