short answer is no.

While there are a number of alternative methods of getting ipod tunes on your X5 stereo...the 6FL cannot be retrofitted either privately or by the dealer,...it is a factory only option. At least, this was the situation for MY2007, but I doubt that has changed for this model year.....

There are a number of exisiting threads regarding various alternatives and the pros/cons of many (you might want to search for a few of these...)....most agree the 6FL is the superior choice when both sound quality and ipod/X5 interface are taken into account.