I've got a 99 Maxima SE, 90K miles.  Recently, after driving it for a
little while, my entire instrument panel goes crazy.  The speedo might
shoot to 90 and stick, the tach might stick at 3000, or they all might go
to 0.  Also the digital odometer stops displaying and stops recording
miles.  

Sometimes it comes back after driving a while, usually it doesn't.  It
seems to be somewhat related to heat, as it usually doesn't happen in the
morning, it seems to have gotten better as it's gotten cooler, and it
always works after sitting overnight, but just shutting it off and
restarting it doesn't fix it.

Any ideas?