Hey guys, I've been meaning to reply to this thread.
I was having the *exact* same problem as shown in the original pictures. The white residue after leaving the dash under cover for a while and the terrible shiny sticky dash after being in the sun. I've tried all sorts of cleaners, chemical free, 3M aerospace 303 protectant, interior cleaners from Germany - nothing worked.
I think I've finally found a solution (touch wood), it's been months since I applied this treatment and I haven't seen any sticky dash or white residue since!
The bottle looks a bit rangi but it has worked great for me. You just dab this on with a small sponge and leave it to dry.
This is the site I ordered it from: http://www.stickymeltingsolution.com/
The exact bottle I ordered was the US$38 single bottle
Sticky Melting Solution Cleaner Single Bottle - USD 38 This is One bottle Cleaner for touch up and minor cleaning touch up.
The shipping is $US12, so US$50 all up.
The guy, Sam, responds pretty quickly to any emails on
[email protected]
It has worked great for me, I'd recommend giving it a go.