Ever since I bought my new '03 SE, I've heard an annoying rattle in the driver's door, top up or down, window up or down. My local dealer couldn't fix it after fiddling with door innards (I couldn't bear to look at door innards, a gory sight, I'm told).
However, to his credit, the service manager called me today, unsolicited, and told me there is a (new?) technical service bulletin out for just such a rattle. The dealer will replace a belt molding, whatever that is, which has redesigned clips. He said that should fix it.
Didn't know if others were having a similar issue. Miata.net doesn't list this TSB, so thought you might like to know it's apparently out there. If anyone is interested in the follow-up, I'll let you know how it goes.
Alan Rattled owner of MiniMi the '03 SE