I also have a 2004 RX330 with a cracked dash. It was said that heat, expansion, contraction causes this... Should this happen on vehicles less than 10 years old???
I don't think so myself, but it's been a documented problem on some vehicles. I know Acura has had issues in the past with this problem. Your vehicle is 10 years old, far out of warranty, so your going to have to live with it or replace. Sorry.
It happened to my 2005 Lexus RX330 in 2011. I talked to he Lexus dealership and their regional manager. The regional manager offered me the parts ( the whole front dash board ) for free but I was responsible for for labor ($650), which I was glad to get it replaced.
Search Lexus RX 330 Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Lexus RX 330 Experts