Goofs

In the first two mini-series, the Visitors spoke with an electronically modulated voice. The sound processing, however, was dropped for the ongoing series. This created a continuity problem with the two mini-series as the Visitors were able to infiltrate human strongholds and vice-versa without their different voices giving them away.

In the original mini-series V (1983), it is clearly stated that visitor ships cannot travel faster than the speed of light (although they can closely approach it), meaning that voyages between their planet and Earth would take several years one way. However, in the TV series, there are numerous incidents of visitors who are summoned to Earth from the home planet, often to deal with problems or for special expertise, and who then arrive just a few weeks or even days later. While seemingly a contradiction, it is also possible that the Visitors had originally lied to the humans about their propulsion technology, not wanting to reveal that they possessed faster than light travel.

Certain main characters' immediate family, notably Robin's two younger sisters and Elias' father Caleb, were left alive at the end of V: The Final Battle (1984), but are never mentioned in the ongoing series.

The Visitors were implied in the original V (1983) to be at war with another alien species, but this angle is never mentioned in the ongoing series.

Now that we know that the 'Visitors' are lizard-like aliens, it seems pointless that they continue to disguise themselves as humans, or continue to use their human names, especially when they are on the motherships. Obviously this was done to reduce makeup and effects costs, but it doesn't make sense in terms of narrative.