That diecast XB on ebay isn't very accurate though - a little bit too Dub-City in its proportions. Particularly the grill is quite toy like.
The proportions of the Aoshima kit are quite good but I've heard the scale is more like 1:23. As Dyno Davo said - it will take some work to make stock - the main things being removing the wheel arch flares, removing the roof spoiler, and removing the concord nose and creating a stock grill.