UPDATE 12/6/22: As expected, tonight's Xbox and Bethesda Showcase brought the official unveiling of Forza Horizon 5's Hot Wheels expansion.
Set in the sky above Mexico, this pack contains what Microsoft desribes as Forza's "most extreme tracks ever devised" as well as the ability to make your own from 80 pre-set pieces. 10 fresh motors include the 2021 Hennessey Venom F5 and the 2000 Hot Wheels Deora II.
The expansion will launch on 19th July - here's a first trailer.
ORIGINAL STORY 9/6/22: An expansion for Forza Horizon 5 has been spotted on Steam, via a hastily-deleted store listing.
The page revealed that Forza Horizon 5 "Expansion 1" would be: Hot Wheels.
Yes, it's another tie-in with the famous toy car brand, which has previously featured in Forza games, and also makes officially-licensed Forza car toys.
A listing which included the Forza Horizon 5 Hot Wheels expansion was briefly glimpsed on Steam last night, and posted to reddit.
Shortly after, the listing was hidden - though an archive of it remains accessible.
It seems like Microsoft will lift the lid on this expansion in the coming days. Sunday will bring the company's Xbox and Bethesda Showcase at 6pm UK time - keep an eye out for it then.
"Playground Games delivers yet another gorgeous and enveloping pocket holiday, smartly restructured but reassuringly unchanged," Oli wrote in Eurogamer's Forza Horizon 5 review, recommending the racer.