[Michele]

The party is obviously part of the Swedish diplomatic personnel, and they are traveling to Berlin with plenty of additional space on their vehicles because they are going to pickup and evacuate some personnel and stuff from the Swedish embassy. Their vehicles are painted white and sport a large Swedish flag.

Verifying this will be difficult, as communications will have broken down everywhere, and also because actual such convoys were incredibly doing the rounds even while the last shots of the war were being fired (they were going to POW and concentration camps, but those are details). Naturally, one stubborn and/or Nazi diehard officer could still refuse free passage until he gets clearance from higher ups - which means at the very least a long delay.

They can go away in the same way, openly heading for either the Danish border or a port in Allied hands.

As to the type of opposition, at this time anything goes. You could have Volkssturm old men equipped with StG 44s, just because nobody managed to deliver them to more deserving units.

Another source is C. Ryan; better for the ambience and personal anecdotes than for general military history, but that is probably what you need.