This issue has persisted since the first Forza Motorsport on the original Xbox. The S14 Silvia model is identical between Forza Horizon 5 and Motorsport, so this comparison GIF is not out of place. However, it assumes the GT7 model is more accurate, and after some investigation I have come to the conclusion that it very much is.
The front end on the Forza model is disproportionate. The front bumper is unnecessarily big, the headlights are oversized, and for some reason while importing the model from any previous Forza game the Trial bumper indicators got stuck in the S14 model.
The side line of the Forza model is not round enough, almost shapeless. The roof is not round enough. The incorrectly sized front bumper is very noticeable here.
The taillights are disproportionately big, similarly to the headlights. The rear bumper lacks shape. The stock spoiler is too thin. The exhaust tip is very incorrect.
And as if this wasn’t enough, the Nissan Silvia S14 Zenki in Forza features 5 (used to be 6) aftermarket body kits made for the Kouki. You know, the S14 version we got in Horizon 3’s DLC. This has been the case since Forza Motorsport 1. Here are three of these kits.
Bomex:
C-West:
INGS+1:
The same 3D model was spotted in the new Forza Horizon 6 gameplay demo, as indicated by the wheels and front bumper size
The S14 Silvias in Forza need a rescan urgently