Hey, since nfsunlimited is still up and running, i directly linked to their site, so its not going over archive.org.
NFSUnlimited is using an unencrypted http connection, so your browser is probably simply warning you not to give sensible data away on that site.
If the warning comes up, simply click "Advanced" and "Continue to nfsunlimited.net" (message may slightly differ dependeing on your browser).