[wamcneil]

Hi All,
My rearview mirror fell down and revealed a loose sensor underneath the rain sensor. Some research reveals that this is the condensation sensor:
http://www.e90post.com/forums/showthread.php?t=272034
This little sensor was apparently adhered to the windshield in the opaque black area just below the rain sensor. The single layer of clear acrylic adhesive has an oval 'slot' cut out of it down the middle. I'm not sure if its adhesive failed, or if the windshield was replaced and the installer tried to get it to re-adhere. There is no trace of the adhesive on the windshield, so I'm guessing the latter.
Does anybody know how this should be reattached? Normally I would slap a bit of double-sided tape on it and move on, but I'm wondering if there is a reason why the factory used a single-layer adhesive and not double-sided foam tape. There are some exposed electronics on the glass side of the sensor, like maybe a thermocouple (the bit that was broken in the linked thread above).
I was able to peel the adhesive off pretty easily, so I have a nice clean surface for reattaching it.
The new part (64116928326) looks like it comes with a positioning jig to set it centered and about 1/4" down from the rain sensor. Doesn't look to me like positioning is all that critical as long as it clears the mirror base clamshells.