No, I haven't tried all of my cars again yet. I'm just getting settled in from moving and am finally having free time to do so. Btw, my time was for 1/4 mile, not sure what it would equate to for 400m.
Also, I've managed to get a couple cars to within a hundredth of my previous bests. I have read that some are only getting within .020. Could just be that I had that much left in mine and I hadn't achieved my best possible run yet. I don't know. I'm still managing pretty consistent times and there wasn't much fluctuation in my times before. But I haven't had much time to test either so it could just be an anomaly.