Interior IR Sensor cover missing

[Overdrive]

I noticed this going on about 3 weeks ago, and just remembered to mention it on here. What I'm talking about are the two IR sensors that are a part of the alarm system that sit up near the roof latch and rearview mirror. They have those dark plastic covers over them, one of which went missing, seemingly out of nowhere.

The one that is still in place is held in rather loosely by whatever little plastic arms it has to do the job, so I'm concerned that it too may take off one day, especially on a day of top-down driving. Has this happened to anyone before? Do they just need to be replaced by newer pieces? Does it affect the functionality of the system at all if the cover is not there?

I have no idea when it could have fallen off but it would have had to have been in the last month or so when I started driving the car around again regularly. I figure it has to be somewhere inside the car still, so I'm going to check under the seats and see if it may have slid under one of them or something like that, otherwise I have no idea where it could have gone and will have to simply consider it lost.

Does anyone have a part number for these buggers? I'm hoping they're not one of the items that still carries the Porsche Tax.

Thanks!