Today I cleaned Bozo's trunk.  First time I did it, and yes, it was
needed.  I always assumed the trunk would stay clean enough, since it
is normally closed.  So far for that idea.  I guess all that black dirt
and grime should have given me an idea, but I really only discovered
the problem from things coming out of the trunk with dirt on them.

Anyway, I noticed a little pool of water around the positive battery
terminal.  Years ago I drilled some holes in the rain conduit around
the trunk opening to mount my MP 3 player in the wasted space
above the battery.  When I removed the thing, I left the screws in
there to plug the holes, except one small hole, which was too close
to the next screw.  I put some silicone glue in the small hole, IIRC,
but that was gone.  So the hole had been leaking water right on the
positive terminal.

It did not seem that the water had bridged the gap to the negative
terminal, but I am now wondering whether this may in some way be
connected to the flat batteries I experienced a couple of times
earlier.  Maybe enough conduction through the wet carpet or so
to drain it?  Though on the other hand, you would think the
battery would have enough energy to vaporize a bit of water
easily without becoming depleted.

Might also be related to the random engine cut-outs Bozo has been
having, maybe.  Road roughness splashes some water, battery voltage
drops enough to cause a problem, battery vaporizes water, welcome
back engine, let's get out of the way of that SUV.

One of the good things of having a Miata with lots of aftermarket
goodies: you always are learning new things.

Leon