We have two stock VW vehicles. 2010 VW Jetta TDI (2.0L L4 DOHC 16V TURBO diesel) and DSG tranny. A 2017 VW Tiguan, 4 Cylinder gas Engine 2.0L, 6-SPEED A/T with the AWD (we can get ice, snow, and mud here). Since we live 2.5 hours from any VW service center I do what maintenance I can. I'm...