When Donovan rescues Robin in the alien craft, Robin is standing behind him on his right side but when he flies it upside down she is on his left which means that the image has been flipped.
During the attack of the Visitors to the rebel camp, one of the girls is seen playing with an E.T. toy.
The resistance is seen sending a radio signal in the hope that it's picked up and deciphered by an enemy of the visitors. This however is never followed up on, and is never mentioned again. However, creator Kenneth Johnson published the novel V:The Second Generation and it's revealed that the visitors enemy is a race called the Zedti, who come to earth at humanity's request but turn out to be even worse than the visitors are.