So yesterday a mate of mine went to test drive a car. It was advertised as a MY00 WRX with STI transplant.

Turns out the car was a GX before the transplant work went ahead.

So, what makes a WRX a WRX? Is it OK to claim this car as a WRX converted to STI spec? Would you purchase a car like this yourselves, now knowing it isn't quite what you thought it was. Does the GX/WRX distinction matter in this case?

Please discuss.