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.
Well, the GIF speaks for itself. Gran Turismo reused the low quality PS2 model of the Zenki back in their PS3 games. And when it returns to GT7, it gets fully remodeled from the ground up. Or perhaps, the one in GT7 is a brand new model because the one from previous GTs is the Aero, while the one in GT7 is the Type S.
Good thing it contains Aero parts, which are available in GT7. These parts got modeled from scratch as well.
Here is the same car as it appears in the first Forza Motorsport. As you can see, it is marked as a 1998 model, despite being the pre-facelift car, and it uses a different front bumper to the one that is used today. The last time this front bumper would be available was in Forza Motorsport 2 as a Forza Race Front Bumper option.