"Spartan"? Seriously? Spartan means "rigorously simple, frugal, or austere"
We have a partially painted dashboard to coordinate with the body color. We have padded dash pieces to coordinate with the interior seating. We have chrome--yes, genuine chrome functional pieces (fresh air vents) along with coordinating textured chrome trim. We have an integral map light built into the glovebox door. Our high quality instrumentation by VDO features genuine chrome plated trim. The seats are thicker and considerably better built than many small sports/touring cars of the era; look at anything from the fair isles of Great Britain to compare. We have a lighted genuine chrome bezel assembly around the shifter on the automatic versions. Perhaps as merely a throwback to the 1950s, but present throughout production, we also have a number of genuine wood pieces: console box, bows on either side of the windscreen, and the speaker grille--also on the hard top. The MB-Tex, more common than leather at the time, was and still is basically bulletproof under normal circumstances and w/o compare. The 230s and early 250s also featured more interior chrome including rear view mirrors and additional trim. Quite beautiful. Hardly austere.
While you cannot compare this to a true luxury car of the era, say a Rolls or Bentley, compare to a comparably priced "luxury" car of the era and I think you'll find that those that exude any kind of luxury at that price point would have had chrome plastic, fake vinyl wood trim, etc.