Goofs: Just after Spike rescues Daniel and Arcee and the latter transforms, her vehicle color is all white when she drives away.
When Monzo is torturing Daniel, he is colored red and black, like Vorath.
It's safe to assume that the weapons on Fortress Maximus and Scorponox are pretty powerfull, way beyond the power of a transformer weapon. Same would apply for their hulls/armor. Then how come Cerebros/Spike can blast his way into Scorponox so easily and Arcee her way out, and Fortress Maximus and Scorponox weapons don't even make a scratch on each other.
In one shot, right before the autobots enter Scroponox, Prime has a yellow (golden?) grill, square lights and no sidemirros.
In the next shot, he has a yellow grill, round lights and sidemirrors.
When they are inside and enter the room where they are captured, he has no sidemirros, a yellow grill and rectangular lights.
Changing colors of parts or even whole transformers happens often throught the whole series, but rarely this much in such a short time for the same transformer.
When Streetwise and Blades were shot by Nightstick, Streetwise's entire forehead was red.
In this episode, Groove's eyes are blue. They should be gold, like his face.
The plasma energy chamber was created millions of years ago by the Quintessons... and its timer can be programmed for ten minutes?
Chromedome says something to the effect that the Headmasters automatically revert to their vehicle modes without their heads. Why, then, in part 1, were the Autobots standing around headless, while their heads were being converted into exo-suits for the Nebulons? But okay, let's say that this feature engineered after they became Headmasters. This creates a new problem, though. Remember back in "A Decepticon Raider In King Arthur's Court" when Warpath said he was so low on energy, he couldn't stay transformed? Does it still use up energy for the Headmasters to stay transformed, then? What if the Nebulons who form their heads never come back? Would they revert to headless robot modes when they ran low on energy, or just run out 'till they died?
Say, shouldn't Cybertron's close proximity to Earth be tearing the planet apart, as it did in "The Ultimate Doom"? Optimus seems blissfully unconcerned about it. Granted, a few trees falling over really isn't a big deal compared to the Sun going nova.
And just when Galvatron thinks he's got Cybertron within his grasp, Ultra Magnus and the Protectobots launch an ambush...including First Aid, who is toting a gun and firing away with the rest of them. Isn't this the same First Aid who said in "The Ultimate Weapon" that he didn't believe in fighting and literally wouldn't raise a weapon to save his life?
In this episode, Galvatron has commissioned the Combaticons to build a giant rocket engine for Cybertron. The Combaticons? Sure, we've seen that both Onslaught and Swindle have some technical skill, but wouldn't this be a job for the Constructicons? We know they're still alive; we just saw them in part 1 of this story.
When Daniel transforms in to Arcee's head at the end, he's still wearing his exosuit in the shot where he's inside her head.
Streetwise was also missing his lips and his nose when Nightstick fired at him.
When the Autobots are celebrating the rebirth of the golden age of Cybertron, Bumblebee can be seen among everyone cheering. However, he was recreated as Goldbug three episodes ago!
Caliburst: Not so fast tough guy!
Zarak: Yes, not so fast Galvatron.
Zarak: I have your boy, and your Autobot friends! They are within my city banks, and when you die, they all die!
Spike: Don't make any funeral arrangements yet!
Scorponok: Autobots, diiiiiiiie!!!
The following characters introduced in season 4 have not been referred to by name in the episodes: Chromedome
After the Autobots are trapped inside Scorponok, Blades is standing with Cyclonus and the Combaticons.
Maybe Vortex was supposed to be there instead (they both transform into helicopters).
To add on to what was mentioned about "Rebirth" being only 3 episodes - it would make sense to extend the series to 5, since certain other transformers were not introduced:
Powermasters (transformers who's Nebulan counterparts transformed into their engines, without whom they couldn't transform - Optimus Prime would change into a Powermaster, who could also transform into a giant robot);
Autobot Quickswitch (Sixshot's "son", who could also change into 6 different forms);
The Targetmaster Seacons (6 Decepticon sea creatures that combined into Piranacon; the 6th member became Piranacon's weapon and was thus interchangeable, except for Snaptrap, the main body);
Sparkabots and Firecons (transformers that had sparks fly out of them); and
Monsterbots (3 Autobots that transformed into monsters).
Last episode to be animated by the Korean studio, Akom.
According to David Wise, the Rebirth episodes were originally going to be five parts, but due to budgetary constraints and the Headmasters and Targetmasters being the last line for the Generation Transformers, it got shortened to three.
At the end of this season, the only characters not reffered to by name were Point Blank, Crosshairs, Apeface, Skullcruncher and Weirdwolf who all didn't seem to play any major roles in the Transformers Universe.
All of the 1987 transformer toys were introduced by this episode, except:
1) The Monsterbots (Repungus, Grostuque, Doublecross)
2) The Duocons (Battletrap, Flywheels (he appears in the credits but not the show))
Optimus Prime is the only character to appear in the first episode and the last episode without any change in appearance.
First, last and only appearance of Fortress Maximus.
Spike now turns into the head of Cerebos who turns into the head of Fortress Maximus. He is a double headmaster.