I missed out on a few Forzathons and couldn’t earn the cars. Will they be available some other way in the future or are they locked away from me forever?
Nobody can really answer that but you might be able to get them in the auction house
More info here though
https://forums.forza.net/turn10_postst133049_How-to-get-Exclusive-cars--not-in-the-Autoshow.aspx
You can always try the Auction House. I know its not very consistent for actually getting what your looking for but I’ve snagged a few HW cars lately so ya never know.
I have managed to gather all rare cars in the game, I can make a deal so you can have some or all forzathon cars. I prefer to use Discord for sales as the message system is very fast and reliable for sales. honestly the xbox app is just too slow for car sales where the cars usually are up for maybe a second at best sometimes. If you want to though, the offer is available.