[DeTomaso] Late model window motor

[Chris]

Does anyone know of a window motor replacement for late model cars (9000
series)? Switch and all electrics test okay, the gear looks worn but not
broken, the motor runs but is very tired sounding and extremely slow in
movement. In fact it's slower going down than going up.
I've regreased the motor gear, removed/cleaned/regreased the regulator and
track. Even removed the window to relieve the weight, the motor still acts
the same. 
Took the motor to the local electrical repair shop where he said it was
working so there was nothing he could do. I told him it's okay without a
load, but once connected to the regulator and track, it's slow again. His
only suggestion was to check the ground. 
Contacted a few vendors, their suggestion is to replace with older regulator
and motor (+/- $500) and/or install the Vader system (+/- $750). Looking for
alternatives before spending that much on a window.
Thanks,
Chris