Thanks for the reply djkronik57
I originally suspected the alternator as well. However, I have a brand new Interstate battery, and I've put it on a CTEK charger for several nights in a row with no effect to the outcome. I've unplugged it from the charger, tested the voltage off the battery and gotten 12.7, gone to crank the trunk and still seen the issue. On top of that I've monitored voltage while driving with my cheapo OBD tool, and it is pretty consistently in the 13.5 to 13.9 range. That leads me to believe the alternator is fine, but I'm open to any additional input.
I'm still driving w/ the instrument panel "free floating" and sitting atop the steering column. Haven't seen the issue in 2 days. Going to leave it like that until Saturday when I'll have more time to tinker w/ it.

 

UPDATE:
So I'm all but convinced my instrument cluster is bad. According to the FAQ page on the GAP diagnostic website https://www.gap-diagnostic.com/faq/ a used cluster can be reprogrammed with their tool (along w/ help from their support team). I saw in another thread where there is a cluster repair place in Northern PA that can remove the memory module from one cluster and install it in a used one for the price of $450.
I'm thinking for another $100 I can buy a BT GAP tool, and then buy a used cluster for less than $100.
Anyone have any experience w/ the GAP tool and reprogramming used clusters?

 

I emailed GAP, and got a response back from one of their engineers named Patrick. He said there is an additional "fast lane service cost" of 25GPB (about $33 US) for the reprogramming of a used instrument panel. Also, for anyone wondering, he indicated they will only raise the odometer value, not lower it.

 

Update: I purchased a used cluster from eBay. It was a 05'-06' cluster even though mine is a 07'. I purchased the fast lane service from GAP and installed the cluster without any problems. It's been installed about a week now and it seems to have solved my problems. I'll report back if anything changes.

 

Congrats WYRover! Thanks for the update

I think I'm going to pull the trigger on ordering the GAP tool today

 

Hope it works out for you. Also like they mentioned you can only raise the mileage and not lower it so if you get a used cluster make sure you get one with lower mileage than what you currently have.

 

FIXED!!
Used instrument cluster from ebay ($70) + IID GAP tool ($538) + GAP diagnostics fast lane service ($33) = one happy guy
Thank you to Patrick at GAP Diagnostics for extremely fast and friendly service!
Also, thank you to everyone here for your responses and help. Hopefully someone down the road will find this thread (and WYRover's) useful.

 

For anyone wondering, it is a very simple and straightforward process. I was going to type up a "How To" procedure. However, I believe that would be distributing information that is proprietary to GAP Diagnostics.

 

I’ve had the exact problem with my 2007 RRS for a few weeks gradually happening more frequent, read a load of post on various forums and most pointing to instrument cluster.... took it in to local garage couldn’t pin point the fault but suggested faulty cluster, then took to Land Rover paid £90 for diagnostic they came back “suspected cluster” Quoted £713+ vat and £46.50 for labour, tried looking online to get a cheaper price for new cluster which was a waste of time but worth a shot! Been told used clusters are a waste of money so wasn’t going to risk spending £300 one on them.
In the end had to bite the bullet and pay over £900 a couple of days ago for new one and up to now car is running good as new!

 

Went to the dealer. Just describing to him the Christmas tree lighting and he said 100% it’s the cluster. He also said there’s no reason to purchase Rover bulbs as many have stated.