Most Buick cars, and in fact most other GM cars, have this defect. The power window mechanism breaks - usually cheap plastic parts break in the power window pulley assembly. GM dealers will only replace the entire assembly, to the tune of $450 per window.
Complaints From Other Buick Owners
Many, many Buick owners have written to say they have had to replace most or all four power windows assemblies, and some even had to replace the same power window assembly multiple times. GM has not changed the design of the replacement parts, so once fixed by the dealer, the problem still exists.
The best way to deal with the power window failures is to get the power window assembly from a salvage yard. A lot of people get sick & tired of replacing these again & again, & tape up the window permanently.
Currently there is no recall for the power windows, because it is not a safety issue (according to the NHTSA). So far, a class action lawsuit has not been filed. At the moment, the Buick Bonneville has the most complaints on file, closely followed by the Buick LeSabre. Just to give you an idea of the wide range of GM models with this defect, we also have the same complaint for the Buick Century & Regal, Chevy Cavalier, Impala, Lumina, Malibu & Silverado, the Oldsmobile Alero, Buick Grand Am & Buick Sunfire.