Having owned quite a few V-Dubs, I have learned the hard way to always use VW spec oils and fluids. I change all my own fluids, and use shorter intervals than recommended - it helps to always be on the lookout for clearance specials on VW spec fluids.
To clarify, the recommendation was 0w40 or...
If you've got one, it's likely there are more.
I use larger bait stations outside (to kill them before they come in).
Inside, I use snap traps and glue traps - and a couple small bait stations (just in case).
It also helps to seal up areas where mice can gain entrance. I prefer...