I also ask them not to wash my car and get the service advisor to write this on the work sheet. I put my ‘do not wash’ hanger on the interior rear view mirror and tie a ‘do not wash” tag on my keys. I also try and ensure my car’s clean whenever it goes into the dealers for any servicing, warranty or repair work so it’s easier for the service advisor to agree it’s damage-free when they do the walk around to check for any existing damage. I think some forum members also take photos, so if any damage does happen, they can show it happened while on the dealer’s premises. Overkill? I don’t think so, after having my mk5 Golf scratched while in for service a few years ago but I only discovered the damage when I got home so couldn’t prove it happened while at the dealers.
I also take a photo of the mileage reading, so I can see if it’s been ‘road tested’ (shouldn’t need to be for a standard first service).
Provided the oil meets VW spec (which it should do if it’s what a VW dealer is using for servicing), it should be OK. I did see that the oil top up kits that my dealer is currently selling were also Mobil oil.