Yes, the mount points are different between a G2 and an ITR because the G2 has a middle mount, plus the bodies are a slightly different shape and width.

Anyway, my input on the subject: an ITR spoiler on a non-ITR is just plain dumb. Why? It serves no purpose at all besides aesthetic value.

Here's an example, once again pertaining to the RX-7 world which I know so well. In the second generation (86-91) RX-7's, we have three different spoilers. Bear with me here, this is valuable information. From 86 to 87, there is the flat rubber Sport model spoiler, which is aimed at reducing the coefficient of drag, which along with a few other aero body parts, did very well. Then, in '88, came the "GTU" spoiler aimed at creating downforce for the rear drive wheels, and from 89-91 was an updated, larger version of the "GTU" spoiler. These three spoilers served a specific purpose, reduction of drag ("Sport" spoiler) or increase in downforce (88 and 89-91 "GTU" spoiler.)

Still reading? Good. On Acura Integras, the spoilers are completely for visual value, as in they have no performance benefit. When swapping spoilers in an FC RX-7, you gain some performance aspect, but in an Integra you do it just to look good. The ITR spoiler has no performance benefits, that's why I think it is completely pointless to have an ITR spoiler on a non-ITR.

Thank you, that is all.