I don't have the part numbers handy, but when I did my X5 hitch I had to replace the bumper carrier. I believe the reason is that the mounting locations are slightly different when using the collapsible shocks, vs the similar shaped brackets put in to replicate that mounting structure. Perhaps the mounting location is the same, and the only reason for the new carrier was to strengthen the bumper because of the removal of the collapsible shocks, but be prepared to find out when you mount the hitch.

Also, I recall a change in the hitch sometime after 2003 when I did mine, involving spacer plates on the pentagon shaped brackets. Maybe that was to shift the mounting points for the bumper such that the original carrier still worked, I don't know.

__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue