RandomHero- I`m out-of-touch on `vettes, having sold my final one (Mallett C5) ages ago. I will say that it had somewhat finicky interior surfaces, both the leather and plastics, with regard to what I like on them.

These days my good vehicles get their leather treated with stuff from The Leather Doctor. But I hardly ever do that, not even annually. Otherwise I just use an Interior QD product and if you don`t like the QID you might try the stuff from NextZett/formerly 1Z. The leather in my Tahoe and the other "not too pampered vehicles responds fine to Leather Masters, Sonus, and Ultima, but again I hardly *ever* treat leather.