I'm mostly just giving you a hard time here, but I'm also geniunely curious what the appeal is (of this and non-zip compression formats to begin with).
You ran two passes so that it crunched the file down from 160k to 80 k? You've saved a tiny fraction of a second of download time, but (even assuming I had a rar unzipper on this machine, which I don't, since I just flattened and installed Win 7) you've added half a minute by needing two programs to decompress. I haven't worried about compression ratios since I used floppy disks and a dialup modem. I appreciate that you're digging up obscure Wing Commander files for everyone, but the double-pass seems like a net time loss for everyone.