Takara Tomy, the Japanese entertainment and children’s merchandise company, is celebrating the 30th anniversary of Transformers by including graphics of the tranforming robots cartoon into a Super GT car (belonging to the Team Mach racing team) as decoration.
This crossover is possible because Takara Tomy currently owns 20% of Tatsunoko Productions, the studio responsible for Speed Racer, Macross (Robotech) and other anime. A fictional backstory will be included as well. More info will be announced sometime later.
The actual Super GT car already looks amazing.
[Source]: Anime News Network: Super GT Car Gets Optimus Prime/Speed Racer Crossover Makeover [https://www.animenewsnetwork.com/interest/2014-04-18/super-gt-car-gets-optimus-prime/speed-racer-crossover-makeover] via TFW 2005: Takara Tomy Transformers 30th Anniversary Plans Revealed [https://www.tfw2005.com/transformers-news/generation-1-1/takara-tomy-transformers-30th-anniversary-plans-revealed-179719/].

