I agree that if it said it found 50some channels you either need to press exit or menu again or maybe a save button, or the TV software isn't working right. Remember you will have to re-aim the antenna and rescan for channels wherever you go so get used to it.
What DrewE said though is right for most antennas you would get bad or no signal. I have a Jack antenna and do get some signal when driving because I don't have to raise it, but it gets finicky whenever I turn direction cause it still has to be aimed to work well. You would also have to rescan for channels when driving through new cities so it's not really worth it.