Why does the Volkswagen Sagitar have a front face that looks a bit like the 5th generation Golf GTI? The grille is so big and has the word GTI on it.

Are you sure it’s GTI? The fifth-generation Sagitar is a derivative of the fifth-generation Golf. It just adds a tail to the golf and calls it Sagitar. The high-performance versions of the fifth-generation Golf include the R32 and GTI. Among them, Sagitar also produces a GTI model, but it is not called GTI, but GLI.

That's probably it. I don't know if it will be helpful to you.