(covers information from several alternate timelines)
In an alternate timeline, Captain Jonathan Archer of Enterprise NX-01 encountered in 1944 a Kübelwagen belonging to the Wehrmacht (as indicated by its license plate "WH-52552", but driven by an SS soldier nevertheless) which escorted the Ford Model 51 truck in which Archer was transported as a prisoner, along with a BMW R75 motorcycle that brought up the rear. All vehicles were damaged when American Resistance fighters ambushed the small convoy, and killed their German occupants. (ENT: "Storm Front")
A second Kübelwagen was a short time later seen driving through Brooklyn, New York City streets twice, the neighborhood in which Archer was hiding after his escape from the prisoner convoy. This, or yet another Kübelwagen was with the German search party that discovered the crash-landed Shuttlepod 1 in which the Suliban Silik had escaped the Enterprise. (ENT: "Storm Front", "Storm Front, Part II")
In 2374, the Hirogen gained control over the USS Voyager and utilized its holodeck for the creation of their hunting simulations. One of the scenarios they chose was set in the French World War II-era village of Sainte Claire, occupied by Germans. In order to be as historical correct as possible, they also recreated period vehicles as backdrop for their simulation, including a Kübelwagen, as could be seen on one of the overhead bridge monitor station viewscreens. (VOY: "The Killing Game, Part II")
The Ekosian Chancellery scene with the Kübelwagen was filmed on 29 November 1967 in front of the redecorated offices of Paramount Pictures, including the building where Lucille Ball held office, running neighboring Desilu Studios. During filming, daily routine at, and in the offices continued unabated. (To Boldly Go: Rare Photos from the TOS Soundstage - Season Two, p. 191)
For the "Storm Front" two-part episode, the search party scene was filmed on Monday 26 July 2004 in Griffith Park, along with the other forest scenes featured in "Storm Front, Part II", wheres the entire ambush scene was filmed Thursday 29 July 2004 on the Sable Ranch grounds in Canyon Country, north of Los Angeles. The New York City scenes, obviously utilizing the same Kübelwagen (part of the license plate was legible in the search party scene), were shot later that day and on Friday 30 July 2004 on the Paramount Pictures "New York Street" backlot standing set.  (X)
Only seen on the bridge viewscreen, the in "The Killing Game'" featured Kübelwagen was obviously not filmed on the "Little Europe" standing backlot set of Universal Studios, where the rest of the Sainte Claire simulation took place, but rather on the "New York Street" backlot set of either Universal or Paramount Pictures. However, it is highly unlikely that the scene was actually shot for the episode, as the costs of renting lot and vehicles for what was essentially a throw-away shot, would constitute a flippant use of the strictly regulated television budget. Considering that the comments of the watching Hirogen and Ensign Harry Kim did not correspond with what was actually seen on the screens either, indicated that this clipping stemmed from an as of yet unidentified other television, or movie production.
One of the more prolific German military vehicles, 66,000 units (together with its amphibious Volkswagen Schwimmwagen sibling) were produced during the war, many of them surviving the war to end up in museums or private collections, including the ones featured in the Star Trek episodes. Actually, the Kübelwagen (which translates as "bucket car") was the militarized version of the Volkswagen Beetle (also seen on Ekos), which had begun production in 1938, but whose production was suspended with the outbreak of war – some of the relatively few produced ones appropriated for officer use in the war. Almost seamlessly, the Kübelwagen reverted back to its civilian role after the war, and the Beetle became one of the most successful vehicles in automotive history. As if to underscore the success of the Kübelwagen, it reinvented itself in the form of the military Volkswagen 181 in 1968. While perhaps not as powerful, the Kübelwagen was every bit as versatile and rugged as its American counterpart was, the Jeep, also featured in "The Killing Game, Part II".