We rode the Tomorrowland cars just once, last year, and I know it was in the morning, but I can't remember how early. The line was long, though, and took even longer than you would expect. Plus, once you finally got to drive, you had another long wait to get out of the cars because of a huge back-up. I remember thinking we were wasting so much valuable morning time. We said "never again!" So my advice is, either go really early and avoid any line at all, or skip it!!!