Just to comment....
This is must my opinion... when we the collective in the detailing discussion forum world use the word vinyl and talk about vinyl I "think" it conjures up what's called an "anchor" in your mind's eye wihch means a "picture type" of a fairly generic material.
From what I've seen over the years though is the vinyl used in new cars isn't the same type of vinyl that was used for decades for dashes, door panels and seats for example in a 1967 Chevelle.
Point being... most "vinyl" dashes on new cars are not like the vinyl of old days and doesn't react like the vinyl of old days. It's a lot more like solid hard plastic. It seems to be a lot more finicky than simple vinyl from days gone by.
What I think has happened in some cases is car companies use green or partly green raw materials, that is somewhere in the mix is reclaimed plastics from recycling. Just a guess. Even if the door panels, carpet, headliners, dashes etc. don't contain some portion of recycled plastic these new materials just don't seem to be as dressing friendly as the kind of vinyl that came in a 1973 Ford Mustang Mach 1
You say you want something to "restore" the softness and
suppleness and especially the flexibility of the dash on your 10 year old Lexus GX. My guess is the dash material, i.e. the vinyl... probably wasn't soft and supple to start with but more like rigid plastic.
Please update this thread with what you finally choose to use and how it works out.
