Well I just looked at the cpan source.... autobundle -> _u_r_common -> sqlite -> index -> indexbundle. Which has this:

my @indexbundle =
    (
     {
      reader => "rd_authindex",
      dir => "authors",
      remotefile => '01mailrc.txt.gz',
      shortlocalfile => '01mailrc.gz',
     },
     {
      reader => "rd_modpacks",
      dir => "modules",
      remotefile => '02packages.details.txt.gz',
      shortlocalfile => '02packag.gz',
     },
     {
      reader => "rd_modlist",
      dir => "modules",
      remotefile => '03modlist.data.gz',
      shortlocalfile => '03mlist.gz',
     },
    );
[download]

So in those files, which you could read using CPAN::SQLite