S(t)uck Mondial 3.2 rear windows

What does the dealer tell you the problem is? Is it the rear window lockout switch on the dash, or one or both of the rear window switches on the console? If they can "fix it in minutes" they might just be spraying some electrical contact cleaner down into the switch and working the switch until the contacts work again. That's something you can do at home.

If you're fog lamp switch has ever burned out, it might also cause some damage to the rear connections of the rear window lockout switch (located above the fog lamp switch.) My connections back there were fried due to a short when the fog lamp switch fried itself. (I consider myself very lucky that was all that happened!)

If the rear window lockout switch is the problem, you can purchase a new one from Ricambi or T. Rutlands. However, if it is either of the two rear window switches on you console you're in for some searching. These aren't available anymore as far as I know. Your options are to find a used one out there somewhere, or to talk to your service provider and see what ideas they have for replacing the switches.

If it isn't the switches, then it most likely is just a mechanical problem with the windows themselves. A competent service provider should be able to fix that without it recurring.

From what I hear though, the most likely culprit is the rear window switches. Best of luck, and please let us know what happens! (And maybe another F-Chatter on here can give us some of their ideas for replacing the rear window switches with something that is available...)