How hard would it be to add the...

[Aren Jay]

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[JohnPPD]

I thought that you were getting a Jaguar?

[Aren Jay]

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[JohnPPD]

Here's one with the HUD. I doubt that the HUD would fit. There's got to be some ducting in the way or dash depth issues.
http://cgi.ebay.com/ebaymotors/00-02-03-04-05-Cadillac-Deville-OEM-Night-Vision-Camera_W0QQcmdZViewItemQQcateg oryZ38655QQihZ012QQitemZ220330 119683QQrdZ1QQsspagenameZWDVW

Here's a generic one. You could always use an external dash mounted monitor similar to a nav unit. But for the price, I'd just hit the dear. :P
http://cgi.ebay.com/NEWEST-FLIR-HI-RES-THERMAL-IMAGING-DRIVING-SYSTEM-6375_W0QQitemZ200283151921QQih Z010QQcategoryZ73363QQssPageNa meZWDVWQQrdZ1QQcmdZViewItem

[frdwrnch]

There was a member here on the site a couple of years ago that did this although I can not find the post right now. He used an aftermarket "Double Din" style radio with an auxiliary RCA video in jack and the camera sytem from a junk Caddy that utilized an RCA feed from the camera and it worked. He even had a shot of the screen in his post. I thought that was a neat idea. Good Luck!