I understand wat your saying as in realisticly 92-93 and 93-94 be wrx would be version 1 and 2 in that case. And a version 2 STi is tech the 4th model impreza as such. But if someone said right i've got a feb 97 uk impreza you'd go in your head right thats version 3 so coil packs on top etc. Or i've 99 wrx and you go right version 5 in your head and say right thats got stagered inlet manifold bolt holes and version 3 won't go on it etc. So basically nov92-aug95 version 1 and carry on from there. Don't start trying to be-little other people or be know it all. Not good for business.