I have a 98 Park Ave and the power windows have developed a problem of not working on warm or hot days. When the temperatures cool down the windows work fine, but when the air heats up they stop working. I don't know if this is a motor problem or in the actual power switch in the door. Has anyone else experienced this problem? I'm hoping it's something I can fix. I already asked a Buick repairman and was only told they could fix it for $500, and that is for only one window. If anyone can offer a more economical solution please advise me.