Found this thread on the IS forum - https://www.clublexus.com/forums/is-...-dash-fix.html

This guy's car has the dashboard problem that also plagues the RX. He found a kit that somehow gets rid of the sticky surface and also bought some items to fix the cracks. While the end result was not perfect (fixing cracks is an art), it looks pretty good.

Give the thread a read and watch his video.