It didn't do any damage to your leather or vinyl?
None at all, but the leather and vinyl in my car in better then average for a 10 year old, 90K mile vehicle (it's spent most of it's life parked in a garage, my dad has garage parking at home and office...I leave it in the garage most of the time and only drive it in nice weather). I would be wary of using it on the leather but vinyl is tough stuff. This is not something I would use often (it is a mild abrasive) but more for that one or twice/year intensive cleaning. It's a good product to use to remove years of filth that is sealed in by protectants b/c the surface was not properly cleaned before application...this gives you a clean base to start over with protectants.
The tonneau on the cars with light interiors seems to get the worst of it. Try wiping it down to remove dust and dirt and then driving for a day, then wipe it down with damp white cloth and you will see just how much dirt accumulates there during normal top-down use.
The reason I decided to try it was that I saw it on one of the trusted detail supply vendors websites (not sure which but it might have been properautocare) repackaged and more expensive...but I recognized what it was b/c I use these at home frequently to remove scuffs on my flat painted walls and some of the grundgy stuff that accumulates on the edge of my shower and the nearby painted trim. You are not supposed to use these on stainless steel but I use it on my kitchen sink b/c it takes hard water deposits off faster then anything I've ever used. We have very hard water here and I don't own the sink
So far it's not damaged the sink at all.
BTW: If you plan to do the tonneau, roll bar, seat backs, visors, windshield header, parts of the door panels, etc...plan on buying more then 1 two pack. These things, even the heavy duty ones, are not durable and really get torn up by the stitching and the texture of the vinyl.