Henry, If the 57 models are the same as the 62's, that plate is to mount the blower motor. The "speaker grill" that mounts on the package shelf over that plate, should be the same as the one over the rear speaker (for symmetry). The blower motor sucks warm air from the passenger compartment, in through the grill, and blows it onto the back glass through the long narrow vent on the shelf. I've had several Mopars with the rear defrost option and they were all basically the same design. Regards, Mark Souders 300H Mohrsville, PA -----Original Message----- From: Henry Schleimer <henry.schleimer@xxxxxxxxxxxxxxx> To: Chrysler300@xxxxxxxxxxxxxxx Sent: Thu, Jul 22, 2010 8:58 am Subject: [Chrysler300] 300C rear parcel shelf My car came with a rear speaker and blower options. Loose with the car was nother flat steel plate designed, I assume, to fit the other speaker hole n the rear shelf. I was going to install it to support the shelf but I am urious why it has a 2 ½” hole in the middle (with 4 screw holes around it). t looks like it is designed to mount something but I am not aware of any hing else that goes there. Is it for an air conditioner outlet? My car asn’t got aircon. Thanks Henry [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: hrysler300@xxxxxxxxxxxxxxx o unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx or list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/Yahoo! Groups Links Individual Email | Traditional http://docs.yahoo.com/info/terms/ [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/