Family member bought a 99 Jetta 2.0L and I want to go over it and freshen everything up since we don't know the service history and I'll be taking care of this car.

It says it has G12 coolant. I've never worked on a German car before so I have just about every other coolant besides that. I've read to order online since dealer is crazy expensive. Does G12 come in 50/50 mix and also concentrated bottles? I try to by the concentrated bottles and add my own water to save money.

Any special bleeding techniques for this car? I have an airlift and also lisle spill free funnel but with the reservoir tank on this car I will probably just fill "normally" unless you think either of those would work better?

Where is a good place online to order all the OEM fluids for Volkswagens? I'm going to need coolant, ATF, brake fluid, plugs, etc.