Thanks, I'll definitely have them check the fluid level when I take it in. I tend to think a low fluid level would cause a consistent problem though right? I mean it happened consistently during a 20 minute drive to lunch yesterday, then a five minute drive to the gas station immediately thereafter, but then not again for the next 5 hours (meaning it hasn't come back). Now I worry that it will work perfectly when I take it into the shop and they'll wonder why we're even doing this...