Yes, it probably would be a valuable to Amazon. So valuable, in fact, that it already[1] exists.
So obviously the price would have to be right and of course Amazon wouldn't be paying a large premium.
Amazon already had an internal project that was going to compete with Lyft and Uber. It was called Rides and it was abandoned. Rex Tibbens headed that project and subsequently left Amazon and went to join Lyft as their COO.