You need some GPC - General Purpose Cleaner.
Dilute it 10:1 and wipe over the dash, this cleans it.
Then either leave bare, or dress it in a UV blocker.
Both 303 Aerospace protectant and Vinylex dressings leave the dashboard in a matte finish to reduce glare, but provide UV protection.
Products can be bought at either
www.waxit.com.au or
www.finalinspection.com.au/store.
DO NOY use armoural, it contains silicone. Whilst it makes it look better, the silicone actually draws moisture out of the dash. So unless you reapply it very often, it will do more damage than good.
303 and vinylex and a few other such as Autoglym, duragloss, poorboys, chemical guys etc are all safer options.