Hi!
Actually, the hull IS extended by 80mm/2,28mm scale 1:35. This is a feature only Gepard shows, and no other Leopard based vehicle. So, each track is one link longer than usual Leopard tracks. In the model picture, in my opinion and compared with pictures of the real thing, the gap is too wide now between 3rd and 4th road wheel. The modeller which did the conversion writes about a 3mm spacer that he added. 3mm = 105mm in scale 1:1. So, here is the reason why it looks too wide. Also, it looks as if the spacer is a 3mm profile, so, as built in diagonally, it makes the space even wider, 4,5mm. Unfortunately, the modeller does not write what he did to the upper hull. No idea, in which way he put thinks together without a spacer within the upper hull.
Keep in mind that this is not the only problem of the model kit. There are quite some more kit details which are different from the production vehicle. And also keep in mind that the German Gepard never had side skirts fitted, even if the front and rear fenders are the ones that are used with side skirts. I served 2 years in a Gepard regiment, and, no, we did not even have these skirts in stock.
Andreas