BMW R75
A BMW R75 was a type of motorcycle, combined with a sidecar, that was produced on Earth for the German military by the German automotive manufacturer BMW during World War II. 

In an alternate timeline, a BMW R75 motorcycle escorted in 1944 a prisoner convoy that transported Captain Jonathan Archer of  in an Ford Model 51 truck, and which further consisted of an escorting Volkswagen Kübelwagen belonging to the Wehrmacht (as indicated by its license plate "WH-52552", but driven by an SS soldier nevertheless). All vehicles were damaged when American Resistance fighters ambushed the small convoy, and killed their German occupants.

A second BMW motorcycle was with the German search party that captured Ensign Travis Mayweather and Commander Charles Tucker III, who had come down to Earth to find the crash-landed  in which the Suliban Silik had escaped the Enterprise. ()

Background information
The search party scene was filmed on Monday  in Griffith Park, along with the other forest scenes featured in , whereas the ambush scene was filmed on Thursday  on the Sable Ranch grounds in Canyon Country, north of Los Angeles.  

Though only seen from the right and head-on in "Storm Front", this particular BMW motorcycle type was identifiable due to the very distinctive way the front support bar was attached over the front mud guard, a trademark for BMW. With 16,500 units produced during the war, this was one of the features that distinguished it from its main competitor of similar design, the lesser know Zündapp KS750 (featured in ), of which 18,600 units were produced and which was technically actually the better of the two. Many of them survived the war to end up in museums or, whether or not modified for civilian use, private collections, including the one featured in the episode. Lack of a license plate on the mud guard, which historically should have been there, makes it impossible to determine whether this unit belonged to the Wehrmacht or the SS.

To the general public, the BMW R75 has become the quintessential World War II motorcycle, having been featured in countless Hollywood productions, only surpassed in renown by its American counterpart, the  army motorcycle. Ironically, part of the Harley's engine was, on request of the US army command, based on the BMW's engine.

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Earth vehicles
Ground vehicles