You likely imported the wrong texture or mask. Re-import in NFS-TexEd, ensuring the name matches exactly.
Once both textures are imported, go to File -> Save to write the changes back to the VINYLS.BIN file. Close the tool and launch Need for Speed: Underground 2 . Go to the vinyl shop, purchase the specific unique vinyl you overwrote (e.g., the "Contest Winner" slot), and apply it to your car. You should now see your new custom design. nfs underground 2 vinyls bin file 73 install
The primary tool used to open and edit .BIN files in Need for Speed games [find it on GitHub or fan sites]. You likely imported the wrong texture or mask