Watching Cars 2 multiple times, I wonder whether or not Ivan is really a Chevy truck (the same model as Mater), since the name "Ivan" is of Soviet/Russian origin, so I think that Ivan may not really be a Chevy truck, but a ZiL-130 or GAZ-53 tow truck. These trucks were relatively similar to American models, so I think that he could be based on these models. Another point to support my theory is that the original prototypes of the ZiL-130 that were built in the 1950s were based on the Chevrolet Task Force (the same model that Mater was based on). So I think that the staff of IMCDb needs to research this, a little bit more, and change the model of Ivan if I'm proven right.

Images of ZiL-130 tow trucks:
https://cs2.gamemodding.com/images/750x407/226b1caa22f15584a4ffd2b916edff3668f57- f2d66b1fa8921e1f1a782bec8bc.webp

http://www.toptruck.ru/zadmin_data/car.image/133740.jpg

A ZiL-130 pickup truck that I found:
https://www.abw.by/photos/news_photos/2021/03/21/g0321_05_0.jpg