if they are the same year you can replace the whole wireing harness and both inside fuseboxes as they contain the multiplexer units, 'm assuming the doner car is a Ex if so it's for the ABS..you will have to pull the dash to replace that harrness or option B is to take the cut plugs with as much slack as possible and with a wireing diagram build a wireing harness to connect the 2 multiplexer unit or option C wire it up like a aftermarket system.