If you have a physical DVD copy:
Check GOG.com — they sometimes sell older racing games without DRM, meaning no serial number needed. Wrc 3 Serial Number Pc Games
It is important to note that racing games based on the World Rally Championship often lose their digital distribution rights after a few years due to the expiration of car manufacturer and driver licenses. Consequently, WRC 3 may be delisted from major digital storefronts like Steam. This means official serial numbers can sometimes be difficult to find through legitimate channels, and physical copies on the secondhand market are often the only way to obtain a valid key. If you have a physical DVD copy: Check GOG