I bought a BMW PurExcursion jacket for a trip and ride I’m planning in Bolivia in early January. The week-long, on/off-road ride will go from about 1300 to 4000+ meters on a DR650. I’m interested mainly in the weather performance of this jacket, so I’m asking in this forum as I suspect there may be one or two who may own a copy which seems to have been a one-off idea for BMW. 
Anyway, it will be rainy season there and temps will vary from 70s down to the 40s (and lower with wind-chill, once we’re at the Salar de Uyuni). I‘m looking for something to wear under the jacket as a liner. I currently planning to use a soft-shell, fleece lined Arcteryx jacket with a hood that is wind and water-resistant, under which I’ll layer one or two merino wool shirts. (I rode in 30s yesterday with a Tornado 3, its liner and two merino shirts and was very comfy.)
So, to my question: what would you suggest for wearing under (or over) this jacket if you were going to ride in similar conditions?
Anyway, it will be rainy season there and temps will vary from 70s down to the 40s (and lower with wind-chill, once we’re at the Salar de Uyuni). I‘m looking for something to wear under the jacket as a liner. I currently planning to use a soft-shell, fleece lined Arcteryx jacket with a hood that is wind and water-resistant, under which I’ll layer one or two merino wool shirts. (I rode in 30s yesterday with a Tornado 3, its liner and two merino shirts and was very comfy.)
So, to my question: what would you suggest for wearing under (or over) this jacket if you were going to ride in similar conditions?
