Alfred: Why bats, Master Wayne?
Bruce Wayne: Bats frighten me. It's time my enemies shared my dread.
When Batman is chased by the cops while he is trying to save Rachel, he reaches the roof of a parking lot and stops. A cop orders him to switch off the engine of his vehicle and get out. Later when Batman is chased inside a tunnel, we see a cop asking on his radio what the Batmobile looks like. The Batmobile then zooms past him and he says "never mind". The only problem is that it's the same cop both times, so he knew full well what the Batmobile looks like when it stopped in front of him initially. Probably caused by the order of those sequences being switched in editing, but still a mistake.
Some people wanted the Batmobile to be computer generated, but director Christopher Nolan refused, so it was built from scratch. It can do 0-60 in 6 seconds.