Not long after Smith's discovery of the dead MacPherson, a group of SS troopers bursts into the inn. They're led by Weissner, the brutish head of security for the Schloss Adler, who announces they're here to arrest some Wehrmacht deserters - actually a clever ploy to capture the British commandos without alarming the townspeople.
Figuring they can either die shooting their way out, or give up and figure out what to do later, Smith and the others surrender themselves to the Nazis. Weissner orders Thomas, Christiansen and Berkeley taken somewhere else, but has Smith and Schaffer taken with him in his Audi convertible. He rides in the back with Smith and an armed Nazi guard. Schaffer sits up front between the driver and another guard.
En route to wherever it is Weissner was intending to take them, Schaffer makes his move. Pretending to tie his bootlace, he suddenly opens the passenger door of the Audi and shoves the armed guard next to him out of the speeding car. In the back, Smith elbows Weissner and grabs the other guard's MP40, forcing him to unload his weapon into the driver.
The car careens wildly out of control as a result, and suffers a head-on collision with a large woodpile. Smith and Schaffer survive because they're the heroes.
As for Weissner, in what is probably the film's silliest death, when the Audi hits the woodpile, the startled Nazi is pitched over the front seat and flung headfirst into the windshield. He smashes through the glass with a goofy scream and shoots like a missile over the hood and continues on for several feet before finally hitting the snow, dead.
After recovering (it appears the remaining Nazi died in the crash... somehow), Smith and Schaffer retrieve the bodies of Weissner and the guy Schaffer shoved out earlier (who also died... somehow) and dump them unceremoniously into the vehicle, before pushing the late Colonel Weissner over a nearby cliff in his own car, which, of course, blows up for no readily apparent reason upon hitting the bottom.