[Lee]

Any best practices for removing snow and ice? Also, any good techniques for washing salt off the undercarriage?

[AP]

I just pop down to a petrol garage and hose it down concentrating on the underside. Body work can be washed normally but the wheel arches and udnerside are obviously more difficult to do.
Not sure there's much more that can be done otehr than not take your car out in it at all.
I don't spary too close to the car as I don't want water to get into part thats shouldn't get wet .

Do it regularly as well. I'm sure the car are galvanised well and are unlikely to rust or have issues but I do the same for my car.

[Gran Turismo]

Check out "touchless" car washes in your area featuring undercarriage water jets as well.

Edit: Since you're in Germany, also check for "Textilwaschanlagen" offering an "Unterboden" program. If operated properly, textile brushes won't harm your paint. A good indicator for the latter is the amount of nice and expensive cars (obviously owned by car afficionados) queueing up at such a place.