Someone has posted in the "Modification" Forum about possibly getting this company who manufactures Miata hard top locks, to start doing the same for the S2000. For current HT owners as well as potential owners, it's not a bad deal for $100. They're trying to gauge the interest in these to see if it'd be worthwhile to start making them. Check the links out and vote in the poll as well as send an email so they can make them.

General Info Thread

Poll