My 03 Gx 470 (that I purchased new) has had the same cracking, dashboard issues. Like others it has been parked 90% of the time in a covered, enclosed garage. When it is in the sun, I use a sun shade to keep my vehicle cooler.
Mine started cracking just a couple months after the warranty was over. When I contacted Price LeBlanc, Lexus, they told me they would be happy to replace the dash board at full price!! I figured I could live with a little hairline crack. Now, that hairline crack has spread all over the dashboard! The dash appears to be disintegrating! I noticed some discoloring and rubbed the area with my fingers. I accidentally scraped it with my fingernail, and a chunk came of. It actually looks kinda moldy. I am so disgusted. :chairshot:
I had an old, used, Ford pinto as a teenager, that sat outside, in every type of weather, and was never under (any kind of) cover. The dash didn't even crack on that Hoopdie!
Today I called Lexus Corporate in CA. I am hoping they will light a fire under the dealership here. Although I don't have the resources to purchase a new vehicle now, when I do, I seriously doubt it will be another Lexus.