Seat interchange between 2004 and 2006?

[ChasesDragons]

Hi all,
I was thinking about fitting Leather seats from a 2004 into a 2006 X3 (June 2006 build).

Are there any spec or build changes between these two years that would stop me from installing the older seats - all four, front and rear? I need to take into consideration the rear load covers et al. Neither set have the internal air bags.

Regards