Update on my dashboard situation...
I park in a garage at home and at work so my car is in the shade the vast majority of the time. However, I've been experiencing the melting for a quite some time now. I started using a Meguiar's product with UV protection and it helped reduce the melting (and resulting glare) when driving around.
My car recently had some issues (thread about that ordeal here
) and I ended up taking it to my local dealer (AutoNation Nissan Kendall) and having the BCM replaced. I spoke to the service director and asked about the dashboard; the problem is very well known and increasingly common. In most cases, Nissan does nothing since all of the affected cars are out of warranty. Regardless, the service director tried to get a new dashboard for me while the BCM issue was being diagnosed (which took a week). It was an unsuccessful attempt, however.
My car's dashboard was damaged during the BCM replacement. Because of this, the dealership's service director was able to get Nissan to contribute a new dashboard and it was installed at no charge. The dealership's service department has replaced several other dashboards under similar conditions since they pretty much start falling apart if you are working on anything around it.
If you haven't spoken to your dealership's service department about your melting dash, go do so! There may be something they can do; it's worth trying.