Very brave to travel that far from home in an E39. Gremlins have been awoken and officially released in about 2019. All downhill from here. Ask me how I know, no scratch that. Too many expensive memories. Safe travels. Nice scenery, and any story with dogs and especially Marmots usually gets my attention.

Thanks for sharing.
Oh the E39 M5 performed great and it is fully sorted. Here is a pictorial racconto I hope you enjoy.
There was a long planned wedding in Yosemite and my son had arranged a baby sitter for his daughter at the hotel, the baby sitter got Covid so I was offered the job on 24 hr notice. Off we go! That is what I own the M5 for! (and to one day escape justice into Tijuana

.)
Great drive, arrived at the Ahwahnee in style but they only have Valet parking. Asked the valet if he can drive stickshiift, he said yes. The Valet wanted to keep the car cool so he lowered all windows, and the rear regulator quit...Other than the sparse E39 toolbox I only had one tool to fend against men, nature, bears, and BMW flaws. Second picture. The ladies pretended to drive the M5 while I pretended to fix the window in the day lot. I am sure other campers had plenty of tools and perhaps some of them were BMW mechanics, but we men do not ask for directions nor help. Self reliance.
No bears entered the car for three days and two nights. At the town of Mariposa inside the M5 I found something better than gold, my lost Lancia keys (picture 4), including the only copy I have for the gas tank! I tried to make a copy at the hardware store, surprisingly they do not carry 1974 blank Italian keys...but they sold me a tarp to deal with the air resonance of open rear windows. Picture 5.
With 100 degrees and dry air, nothing like an Ice Cream in Mariposa, where I discovered the ice cream has been patented. Pay up you infringing deadbeats!
Then I went to check a Delta Integrale that could also be fun to drive next time, and perhaps even less reliable. Picture 7. But then again the 330 in picture 8 would fit better at the Ahwahnee, just do not let the Valet guys near it.