A Robot transporter
A Robot transporter was a type of near-ground vehicle used by a race of Robots encountered by the crew of the USS Enterprise in 2266. The transporters levitated just above the ground; they features a cabin at the fore of the vehicle where a Robot driver sat and a larger open flat are to the rear, which could be enclosed in a forcefield capsule to contain passengers; they featured a predominantly red color-scheme.
The Enterprise had been remotely hijacked by the Robots, who landed the ship on their planet and demanded the crew disembark. Once off the ship the Robots stunned the crew and loaded them onto transporters to take them to another location in their settlement. Fortunately the transporter holding the bridge crew spontaneously exploded as it travelled through the city. The forcefield that had been preventing the crew from escaping remained in place long enough to protect them from the explosion, before collapsing to allow their escape from the wrecked vehicle.
Later, when the crew had been apprehended by the Robots once more, another transporter was used to ferry Captain Kirk and Mr. Spock from the Enterprise, where the Robots had just forced them to remove one of the ship's power rods, to the Robots' power unit, where it was to be used to refuel the Robots' energy systems. (TOS comic: "Life Form Nonexistent")