The wheels had flat spots and cracks.  From what I could tell
after the fact, it appears that one of the wheels hung up, which
snapped the cable and sent the plastic piece that used to be on
the cable into parts unknown.

And a really good place to lube if you can get there without
taking everything apart, is right at the top of the assembly
where the cable guide/stop block come together.  It's at the very
top of the window guide toward the rear of the door.

If that part hadn't vanished, I might have tried replacing just
the cable.  However, I was fortunate enough to get a whole
assembly thru a friend, who had *just* bought it from e-bay!
He's going to convert the non-power windows into power windows on
his Laguna so his was not an emergency need and he was kind
enough to pass on the part for the same price he paid for it.
$52.90 - including handling.  A heck of a lot better than the
nearly $205 the dealer wanted!

Iva & Belle.)
'90B Classic Red.)
#3 winkin' Miata