I was driving down Fremont Blvd., heading toward Irvington District from Automall Parkway. I had just turned onto Fremont Blvd. when I noticed something shiny with red on it low in the sky off to my left. At first I thought it was a low-flying helicopter coming towards Automall, until I realized that it wasn't shaped like a helicopter. Also, it seemed to be too low for a helicopter since the freeway was a bit further off to the right (east) than the location of this object. Then I thought it might be a really big remote-control toy. As I paid closer attention, I noticed that the object was actually flat-shaped. More like an upside-down shiny metal plate. And it was REALLY shiny. The sun was glaring off of it. As I watched, it curved further to the left, towards me, over the neighborhood, and then it started to go away from my location, heading north/northwest. Before I could determine anything, it had shot away and was not even discernible in the sky. It went from flying away to being far away in just a few seconds. It was hard to keep track of it, as I was also trying to drive down Fremont Blvd. I couldn't spot it in the sky at all once it took off, though a few seconds later I saw a commercial airplane go over from the east, heading west/northwest, as I was scouring the sky. The airplane looked NOTHING like what I had seen, other than it also had some red on it. And it was flying in the sky. Other than that, it was very different from the object I had seen only moments before. I still don't know quite what to make of it! It wasn't until a few seconds after it had disappeared that I felt any real reaction to what I'd seen. My mind kept trying to make sense of this very odd object in the sky. It flew low, though, so as it went away, tree tops and closer buildings obstructed any further view I might have had.