Thank you very much. I completely agree with you. Finding interior parts in good condition these days is easier said than done. To last 20+ years they have to be taken care of, and sadly that's no longer very common anymore, especially as the cars get cheaper. I'm glad people like you can appreciate the effort that goes into getting some of these parts which to others look like nothing out of the ordinary
Insanely Rare JDM AE101 Optional Rain Sensor
In Japan they had all sorts of crazy and quirky optional extras for the AE101 Corolla, and this optional rain sensor is definitely in the top 3 in terms of it's rarity. For almost 6-years I've only ever been able to see a tiny picture in the original sales brochure of the rain sensor and have never come across one in real-life, until early last week when I stumbled across one myself!

. The only other one I've ever heard of was back in 2005 on eBay so the rarity of these are truly off the scale. It works by sensing the intensity of rainfall and automatically controls your windscreen wipers, varying the speed without the driver having to even touch the wiper stalk. For a full and very interesting read-up on how it works check out this link:
http://www.fujitsu-ten.com/business/technicaljournal/pdf/2-7E.pdf
It was made in Japan by Fujitsu Ten for Toyota Motor Corporation back in the early 90's as an optional extra for a small selection of Toyotas and likely would have been a fairly expensive add-on. It simply plugs into the existing wiper connector for the combination switch and 'watches' for rainfall, while still allowing you full control over the wiper speed using the stalk if you prefer.
I very rarely drive my Corolla in the rain, so I'm still deciding whether I'll install this or sell it to someone who will get more use out of it, but either way it's a really cool thing to have found and another thing to cross off my 'optional extra bucket list'

. The photos showing the sensor on the hood are how it's intended to be installed by Toyota, but if I was to install it on my Corolla I'd mount it on the cowling as seen in the other photos, as I feel it'd look a lot cleaner that way.