I done some research and it turns out that Alex is right on the xr3i and s2 being the same height. the mk3's were different though.

the mk4 xr3i and Rs turbo had the same ride height of 1349mm compared to the other models at 1369 mm.
the mk3 xr3i was 1380mm and the Rs turbo was 1349 mm and all other models 1380mm