2015 Opel Insignia (aka Buick Regal), same drive train as Saab 9-5 NG (2010-11)
1st drain, 41600 Miles/ 67000 km, GM OEM fill (Dexron LS gear oil 75w90), ~0.6L used
- replaced with Redline GL5 75w90, as recommended by Redline.
Rear Differential (NOT the haldex clutch thing, but the actual...