Since cruise control cannot be bought original as spareparts. Can I get one from a crashed car and mount in my car?

The part I was offered is from a 02 wrx and my car is a 04 STI ?

It comes with
harness for enginebay
control unit
arm for dashboard

 

I am also hunting for the cruise parts for a 1997 Sport. Tried to find a kit
once but they were withdrawn due to a recall in the usa. Nothing serious,
the cable on a few cars dropped off the throttle, apparently. It was fixed
with but the kits were withdrawn. That's what I heard.

Don't know about the later cars.