I look at cars for sale almost obsessively, and have only once come across another 2nd Gen RX with the "multi-panel" sunroof. I've seen a 2004 RX330 with this option and posted it here. It sounded like the option was only available for 2004, but saw this 2008 come up for sale recently. Wonder how many 2nd Gen's had this option? Was way ahead of it's time - surprised it didn't take off. Here are some pics of the said RX:

 

The Air Ride Suspension option is quite rare to be seen in the used car listings, too.
Also, the different color wood. "Birdseye Maple?" I dunno.

Anyway, regarding the sunroof: I agree the panoramic roof is a neat option, but I don't think people would use it. I never open the roof on either of the cars I own with moonroofs.

Decades ago, Oldsmobile made a station wagon called the Vista Cruiser. It had all kinds of glass windows for the kids to look out of. It was just a novelty.

 

I'd say that was the rarest option.......

 

That car is definitely a needle in a haystack. Thinking along the lines of a Toyota/Lexus exec as the owner, at whatever the sticker would be, probably would be close enough to just hope over to a GX for the average person.

 

I’ve only seen one in person on the second gen. It must have been something you could only custom order directly from Japan but had to wait months for.

I think the rarest option on this generation is the radar adaptive cruise control. Might only be available on the RX400h but I’ve never seen it even on the hybrid, only a couple times in pics.

 

yea ive never seen; let alone heard of any 2nd gen rx's with the adaptive cruise control. I didnt even know that was a option way back then. I wonder how many second gens out there had this because Ive never come across any that have had it; although i have seen some second gens with the rear parking assist sensors as well as the backup cam and nav.