Sorry to hear of your issues!
We took delivery on 9 Sep and have about 700 miles on ours mostly highway/city but some fire roads and stuff.
So far we have not had any issues with the AC. I do run it in the manual mode and do not use auto. We also run about 1/2 the time with all the windows and the safari windows open.
When I picked ours up, I asked the service manager were there any issues with the HVAC system......he said when they first started selling the Grenadier they had a couple that had to have some sort of HVAC hose replaced. I cant recall the exact wording but something to that effect.
You mentioned the Digital Fuel Gauge.....here is what I found thus far.
Every vehicle I purchase I keep logs of fuel, mx at dealer or myself, receipts....you name it. The reason I mention this is I wanted to test the fuel capacity/fuel economy and have a baseline for MY driving style and conditions.
1. First tank was kind of a bust because it left the dealership with a "full tank" and I could not verify that. I am sure they filled it up BUT I simply trust my fill ups.
2. We drove in all conditions for about 200 miles. Filled up and my data can now be used to see how the Grenadier estimates things.
3. Second fill up was a test to validate the "Fuel Gauge", some MPG calcs from pen/paper vs Grenadier....etc
4. The digital fuel gauge and the low fuel warning came on when we showed about 3/8th of a tank. Doing some mental math and a 15mpg guesstimate, I figured we could drive for a lot longer than the fuel warnings came on. We drove and drove...the warning and the estimate on range did not change. We drove a circuit close to the gas station that has decent hwy/hilly roads and kept on going. Then something changed....the miles to empty started looking like my estimates and it counted down pretty close to a mile on the road. We filled it up with the estimate on the computer showing 8 miles til empty.
We are still driving til we empty this tank so I can let you know based on that if the digital gauge is accurate or not.