The owner`s manuals for my Audis (just revisited the newest one, which is lightyears ahead of the one for the `93 in this regard) are still idiot-level useless. Far below the level of competency that I had as a *child*. All the stuff we have to correct newbies on...only thing worthwhile is that they say to use a neutral ph product on aluminum trim.
Leather Care according to the Audi manuals should be done with "plain water". When required for stronger cleaning, "two tablespoons (!!!) of a `pure liquid soap` mixed with one quart of water". You`re supposed to keep it out of seams and wipe with a clean cloth. Protect with "a suitable leather-care product". Zero mention of how you *really* do anything, much less any specific product recommendations.
(Heh heh, any of the Pure Liquid Soaps I use, mixed to that dilution, would suds for months! And leave a terrible residue on anything.)
I know that Ford works hand-in-glove with AutoInt/ValuGard, so I just ran out to the shop for the Crown Vic`s manual (first time I`ve opened a door on that one for over a year!

). Let`s see what they say..Exterior Care is to be done with Motorcraft products (part numbers provided, wonder who makes the stuff..). Given what they recommend for frequency, I gather it`s nothing special by Autopian standards. For the Interior...same thing. They do give a comprehensive list of products/pns. Wonder if ValuGard makes them...I *will* commend Ford for at least being specific, and I`m sure their stuff wont` do any damage. But it`s *clearly* geared towards non-Autopian types who aren`t very particular.
EDIT: the Ford manual also says it`s OK to use "products of equivalent quality" and suggests different product numbers for US/Canadian owners.
Eh, given that I`ve had leather interiors since the `70s, and keep vehicles a *LONG* time while using them hard, and have only had *one* sportseat bolster redone in my wife`s one car, I`m gonna keep doing what seems intuitively obvious, using products that I know work fine.
And I *still* haven`t had to replace that cracked, utterly trashed, "You gotta get that reupholstered.." leather in the beater-Tahoe

It`s sure not better, but not worse either. Ditto for the `93 Audi with the leather that had *never* been treated properly for its first 15 years and that I`ve only had to do twice in the 11 I`ve had it. Just like my final e36 M3, those both went from "crinkly stiff cardboard" to soft and pliable, and they`ve stayed that way...so much for "you can`t condition coated leather"! Bah, I`ve done it numerous times and it`s always turned out great.