Busy checking for the best option as well for my X3.
My findings so far:
bmw fit the execuhitch - R10000 (R7500 was their price ex labour)
towlink - execuhitch - R7200
Auto pro SX - execuhitch - R5995
Racknroad - thule - R6400
Autotec - bosal - R 4500
Will probably confirm my option by Friday.
Any opinions on the choices?