The third version  would quite possibly have been the most gimmick loaded Transformer in the history of the line, simultaneously being a Powermaster, Headmaster, and triple changer. The Headmaster also would have been a triplechanger, turning into a sort of armored four-wheeled rover (Roller II?) and robot as well as a rather silly looking Optimus Prime head with four vertically aligned wheels jutting off the sides. It seems that when the extra Headmaster gimmick was scrapped, the super mode head remained separate rather than being reintegrated into the trailer hitch such as on the earliest design. Notably, the body of this design is extremely close to the final design.
With the data from the piece price evaluations I was able to also evaluate the average size of LEGO sets each year. As you can see on the chart below, the average size of sets released each year stayed somewhat constant from 1980-1990 until around 2000 which set sizes started to increase. The average set size seems to have peaked in 2008 (which saw the release of the Taj Mahal), but since then it hasn’t fallen to its pre-2000 levels. It seems to have found a new normal around 300 pieces.
Hot Rod first appeared in the Headmasters limited series as one of the Autobot crew led by Fortress Maximus. He became a Targetmaster in the fourth and final issue of the series. However, his Targetmaster partner is called Sparks, instead of Firebolt (though the UK comic would occasionally call him Firebolt). Hot Rod made sporadic appearances, with a few UK stories starring him as the lead, but most of those were set in the past or future. Kup's Story revealed the first meeting between Kup and Hot Rod, and how Hot Rod's influence shook Kup out of depression; and Ark Duty starred Hot Rod and set up the creation of Autobot City. Hot Rod debuted in the main continuity after the loss of many wars to the Underbase powered Starscream, as part of Fortress Maximus' group. He served as an eager soldier who idolized Optimus. However, he was killed during the Decepticon ambush on Klo in the last issue of the Marvel G1 comic, only to be resurrected by Prime and the Last Autobot.
As the number of sets released has increased, the harder it has been for stores to parcel out their shelving space. In order to make more sales, decisions have to be made as to which sets will be carried. Not every store can carry the whole product line (not even all official LEGO stores carry the whole product line). This process will favor the sets that drive sales the most, such as the licensed sets. The traditional boxes of bricks are pushed out of the way for the more profitable lines.
Over the course of the next twenty years, the Decepticons succeeded in seizing control of all of Cybertron, forcing the Autobots to operate from their new city on Earth and two bases on Cybertron's moons. In the Earth year 2005, Prime, stationed on Moonbase One, dispatched troops to Earth to acquire energy for an upcoming strike on Cybertron. The Decepticons, however, got wind of the plan and used the shuttle run to attack Autobot City. A distress call summoned Prime and support troops to Earth. In the fearsome, ensuing, epic battle with Megatron, Optimus Prime sustained fatal wounds, but not before turning the tide of battle and forcing the Decepticons to flee. Despite the efforts of Perceptor, Optimus Prime went offline after passing the Matrix and role of leader to Ultra Magnus. His last words were "Until that day... 'till all are one." The Matrix later fell into the hands of Galvatron, a recreated Megatron, and was finally taken back by the young Autobot Hot Rod, who became Rodimus Prime after bearing the Matrix. In season 3, set a year after the events in The Transformers: The Movie, Rodimus was the new leader of the Autobots.
The 1986 line featured another significant change in that many, if not the majority, of the toys were conceived as futuristic vehicles and bore little resemblance to present-day machinery. This was due to changes in the movie and television series, which leaped ahead twenty years to the year 2005. Many have speculated that this change might have been what signaled the beginning of the end for the Transformers, as part of the novelty of the first lines was the realistic vehicles that turned into robots.
Optimus Prime is the Autobot leader on Transtech Cybertron. On Transtech Cybertron, Optimus Prime is a gifted politician who has forged an alliance with Megatron, the militaristic leader of the Decepticons. together, they helped bring forth a golden age on Cybertron. Transtech Cybertron is unique among Cybertrons of alternate universes in that war has not broken out between factions.
This Japanese exclusive release of Optimus Prime features much more black coloring than the previous releases, and it's (coincidentally) based on the Fast Action Battlers Power Armor Optimus Prime toy, so as to be used with the similarly-repainted Legends Jetfire figure to form the Optimus' powered up combination. For some reason, he has red eyes. This redeco also uses the slightly small fuel tank/elbow tabs from the Battle Damaged release.
This release is another redeco of Cyberverse Optimus Prime, this time with a predominately navy scheme with black accents (which vaguely resembles his Generation 1 colors), and a pair of barrage cannons that can be either held or mounted on his smokestacks, as well as a pair of handheld swords. He is compatible with all his previously released Cyberverse accessories, but not all at once.
Based on his appearance in War for Cybertron, Generations Optimus Prime transforms from a red, blue, and silver robot into an "armored truck mode." He comes with a hand-held rifle that is held via either of its two 5mm posts, and can fold up to store in either mode. He features additional 5mm ports on his forearms, roof, and front-wheel panels. Optimus has a stylized sculpted Autobot insignia on his back, as seen in the game, but it is obscured by kibble.
Prime would make one further surprise appearance in Dreamwave's Transformers: Armada comic series, although it would not be the Prime of Dreamwave's first series. When the Optimus Prime of the Armada universe disappeared, pulled into another dimension by the power of Unicron, the Chaos-Bringer sent something back in his stead: a nearly dead Optimus Prime from that universe, who warned the transformers of Unicron's coming into their universe before dying.
Part of the first wave of TakaraTomy Lost Age: Movie Advanced toys, this Japanese-exclusive redeco of 2007 Transformers Protoform Optimus Prime is given a Generation 1-styled color scheme (which is also based on his appearances in IDW's Transformers: Foundation comic-book mini-series). Protoform Optimus Prime transforms into his "entry" mode. This mode somewhat resembles a cybertronic truck, with false wheels sculpted onto the sides, and Optimus Prime's trademark windows in front. His now-blue flame decoration piece fits to the back of the "vehicle", creating the illusion of a flaming comet's tail (Not sure if this was mean to represent his jetpack blast effect or his atmospheric entry heat effect, which is for no reason: entirely blue instead of hot red). The bottom of the vehicle has small wheels to roll the toy across smooth surfaces.