Hi Geoff,
there 's no need to share the source code.
Just register here with 5, 10, or ... as many accounts you want, and start releasing modding files, patches, even some modded GP4.exe files, to make the game adjustable according to the rules changes of F1 and today's gaming needs.
e.g. add the "internet play"
make the number of teams and tracks per season a setup option,
... and quite many more, I' m sure you know well from CSM - TSM and from worldwide forums.
Give GP4 the boost it needs to become the racing sim of the century and let the gaming industry stand wondering...
After all, GP4 deserves it.