I have just got a 2004 crossfire with the automatic spoiler which is fully functional !
Unfortunately, the spoiler itself is very rusty and has been wrapped very poorly. I was wondering if its possible just to replace this part, how hard a job it is, and where to find one, as a quick google search came up with nothing.
Any assistance would be greatly appreciated!

 

I have not done this myself but this should help.
Look under BODY. Instructions on removing spoiler.
This is for a coupe. Not sure if you have coupe or convertible.
There are a few videos also if you google CHRYSLER CROSSFIRE REPLACING SPOILER.
Jim

https://www.crossfireforum.org/forum...s-repairs.html

 

This is a gold mine!
Thank you very much Jim!

 

They are listed on eBay.

 

Not sure how rough your spoiler is but once you have it off, perhaps a local body shop could fix it up if you can't find another spoiler.
Or do it yourself if able.
Also post a wanted ad in this forum and you might get lucky.
Also check wrecking yards.
Jim

 

Super simple to change
plug and play
download a copy of the service manual, be mindful of the torque.
Disconnect the batttery before you unplug anything
usually a few of them available on eBay.

Look for these pages in the manual for the NA wing. This one is from the SRT section.

 

Here's a link to spoilers for sale on e bay:
Rear spoilers