In the movie Independence Day Captain Hiller (Smith) and David (Goldblum) fly an alien-ship that had been in our possession since the 1950s (explicitly mentioned more than once in the movie) into the Mothership to upload the virus, nuke the ship, and fly out of it.
When they near the alien Mothership, the smaller ship's pilot is overridden and David says something along the lines "I was counting on it".
But how is it possible that the aliens did not notice that the ship coming back was a much older one and arguably of a different make too. And, if they indeed had noticed, why did they take it in? Wouldn't a ship lost 50 years ago coming back seem suspicious?