I thought I'd do a drain and fill of the tranny fluid. More so because the fluid is almost ten years old despite of the low mileage. I was able to get out 3.17 quarts of fluid and it looked clean and red when it was draining. I thought i was wasting my time but after looking at it next to some new Toyota WS ATF, I'm glad I did it. I don't care if Toyota says it's "lifetime" fluid with no need to change it under normal condition. After seeing how dirty the fluid was compared to fresh fluid, I'll be doing a drain and fill on the tranny every 40k to play it safe.
Since Toyota claims that the ATF is a "lifetime" fluid, by doing a simple "drain and fill" that replaces about half of the U341E automatic transmission's 6.9 U.S. quart total capacity at least every few years, your vehicle's maintenance will be far ahead of the average Vibe/Matrix/Corolla owner.