You can edit an important part of human and CPu performances through the magic files. Of course, You should integrate, or optimize magic with right perf text files, and physic file. GPxpatch is needed.
But You can get realistic performances pack that I made for GP4 ( v.1,00 and 1,02 ), and, if You want, can modify for your preferred use.
I don't suggest this, since performances are specific and realistic for the 2002 season...but You are free to do what you prefer with downloaded files.
nicol@cciarri