I had to drill holes on my mount which was for the G25.
Interesting I know that the GT2 fit into some if the existing holes in my Playseat Evo I dint have the G25 on there so I assumed it was the G25 mount holes.
I believe there is a drill hole template on the Fanatec website.
I know, and I downloaded it and almost started to drill using the template. But, for whatever reason, the template did not match the GT2 itself. When I checked and compared the GT2 with the wheelstandpro, I realized that there was a set of holes on the wheelstandpro that lined up with the threaded holes in the GT2. At that point, I realized that I did not need to drill any holes.
Be careful about drilling using the template. Make sure the template actually matches the wheel.