Hoping someone can point me in the right direction. Have a 2004 Z4 3.0, build date 11/2003. I purchased it in April of 07 with 6,500 miles. It now as 29,000 miles and other than the "sticky steering" issue which required a new steering column (a long story) it has been trouble free until just recently. The car never sees snow (stored 6 months out of the year) and rarely sees rain.

Problem started with the soft top motor failing to open the top all the way. Would stall with about 4-6 inches remaining to lock. Heard "cracking" noises in the final stages. Discovered a plastic "deflector", BMW part number 51437110231, cracked and broken into pieces in the top storage area behind the seat. Removed the debris and the top functions flawlessly. Had the dealer order and install a new part. First time the top was opened had the same experience, cracking noises and the new deflector is cracked.

Concern is that the top is "over extending" resulting in the break or something else is going on the will lead to the top failing. No one has been able to explain the purpose of this defector. So I'm turning to the real experts hoping someone can answer the following questions:

1 - What is the purpose of this deflector?
2 - Is it required given that everything works fine with it removed?
3 - Could this be a symptom of a more serious problem to come?

Thanks for all the help, this forum has been a godsend in the past.