I've had my '04 Prius since May of last year and love it. But I've been having a problem with the screws from the clips that hold the cargo cover (the roll-back one) in place falling out. Toyota Canada doesn't have a part number for the screws, so they've had to order me an entirely new cover each twice now. The service and parts departments tell me that only my car has had this problem and they can't explain it. This past weekend, I've had to order my third cover. Has anyone else had this happen in their Prius? Does anyone in the US or elsewhere know if you can order the screws?