Thanks a lot for comments.
Yep, I think the kit wheels are too small, but don't get me wrong, they're correct in the scale. The fact is that '96 spec ITR were released with 15 inches wheels, easily indentified by a 4-lugs bolting pattern. Thats the ones Fujimi provides with this kit. '98 spec and later models were equipped with 16 inches (PCD 5x114.3) which suits better the line of the car IMO, that's why I choosed to go for the Enkeis in 16", but original wheels are not wrong.