Yes, I know it was a rebadged Toyota Altezza with the larger 3.0L in-line 6 (I owned one for 5 years). When I said interior "quality", I wasn't talking about something extremely plush like in an LS430, 4Gen Es330, or the 2Gen SC, with areas of wood-trim everywhere....it obviously was not like that by any means. By "quality" I meant something that was screwed-together well enough to last, using durable materials that didn't feel like they were of bargain-basement quality, and something that I could bounce my large, heavy frame in and out of, several times a day, for years, without the seats ending up looking like something an NFL team had practiced on LOL. In that, IMO, it was clearly the best of the three IS generations, though it lacked the later versions' AWD option and had lousy winter traction, even with electronic traction-aids.
The 1Gen IS also had some really nice interior features inside...not only the genuine-metal polished chrome ball-shifter I previously mentioned, but a shift lever itself that precision-snapped in and out of shift-gates like a Rolex watch, smart-looking chronograph-styled gauges, shift-buttons on both sides of the steeering-wheel spokes (front and back), and a killer stereo. The only things I didn't like inside were the total lack of wood trim, the orange instrument-panel lights, a quirky climate-control system that kept defaulting to recirculate instead of fresh-air, and some quirks in the shift-gate markings.
You're strictly talking about interior durability then and fit and finish, not really quality. Look, there are Toyota Corolla and Toyota Echo/Toyota Tercel models that have highly durable interiors with strong fit and finish, but that does not make them necessarily possess high
material quality and definitely not luxury.
How about certain years of certain Mercedes Benz products that have had so-so durability, and inconsistent fit and finish? Could one really argue those are not luxury interiors? It depends, as those interiors still used
quality materials.
With the 1st gen IS, I very strongly believe that the interior
material quality is average at best, nothing special. The fit and finish and
durability of the interior is very good yes.
With the 2nd gen IS, the interior
material quality was significantly better than the 1st gen IS. This is extremely hard to argue otherwise. However, the 2nd gen IS interior does have some issues with the
durability and fit and finish of the interior.
With the current 3rd gen IS interior, frankly it's too early to talk about the
durability of the interior. A few more years need to go by. Fit and finish seems strong. The interior
material quality is not amazing; depending on who you ask it's either a bit worse or a bit better than the 2nd gen IS interior
material quality. Therefore IMO, it's premature to say the 1st gen IS interior is 'better' or more durable than the 3rd gen IS interior.
Also, it greatly helps in interior discussions (and general auto discussions), to be as clear and concise as possible