Any help diagnosing the following noise would be much appreciated.

The truck is a brand new 2005 Tundra DoubleCab 4x4 (275 miles). It
starts from cold normally.  I drive it at least long enough for
everything to get warmed up.  I then turn it off, and wait between 15
minutes (approx) and 2 hours (approx), and then start it again.  Right
as the starter engages, or a fraction of a second after, I hear a
metallic sounding clang (sort of hollow sounding), though the engine
starts just fine.  If I immediatly turn the engine off and immediately
start it again, I do not hear the clang.  If I wait less than 15
minutes (approx) from when it was last running, I do not hear the
clang.  It does it regardless of whether the A/C is running.  I was
able to get an audio recording and can email it to anyone interested
(it's only a few seconds, so the file size is very small). I live 2
hours from a dealer, so if I can get an idea of whether it's something
to be worried about without the long drive, I'd appreciate it.