So, there's this Game/Anime I've been sitting on for a while for IMCDb titled Umamusume (I promise, if I ever get around watching season 2 I'll make an IMCDb page...) where famous Japanese racehorses are turned in to waifus... The owner of one of the featured horses chanced upon an itasha of his Anime-fied horse
https://twitter.com/seiun0005/status/1614697888843726848

P.S. apparently both vehicles are owned by a grandson of another horse owner, though his horse hasn't become a horse girl to my knowledge.