If rebels can steal a hunter chopper and rebrand it as their own, then I think it would be plausible for them to steal other vehicles as well. I've compiled a list of every Combine vehicle that I think is possible for rebels to steal and repurpose for their own.

1. APC: Very similar to the rebel chopper. Just a vehicle that has the lambda symbol spray painted on it with some yellow stripes. Works identically to the regular APC, but is friendly to resistance and hostile to combine.

2. Rollermine: Just a port of the orange rollermines you see in Ep1, added to the spawn menu for convenient deployment. Turns red and explodes after taking too much damage to simulate the instability it experiences in Ep1.

3. Dropship: Yes, a dropship is a synth and that means it's technically alive and much harder to steal, but I like to imagine that the dropship has no free will and is just controlled by an interface inside the container. The reason I think this is the case is because in HL2, dropships seem way too coordinated; they stop at the perfect position and release their passengers while remaining perfectly level. This isn't the case for when it deploys APCs and Striders, which seems more natural. Additionally, when Dog attacks a Dropship, it severs the connection between the container and the Dropship, after which it seems much more organic in its flight as it attempts to shake Dog off of it. Because of its apparent lack of free will, this would allow the rebels to control the dropship and potentially change the turret's targeting. It would have a massive lambda symbol painted on the top and yellow stripes on the container.

4. Turret: Just the turrets you can find in Ep2 that the rebels used in the antlion infested mine. I'm not sure if they're already in the spawn menu, it seems like something that would be added. If it isn't, this would be very convenient to have available.

5. Drones: Automated drones such as manhacks and scanners could very easily be captured in a raid and dissected to retarget their sensors. I'll go into more detail into each

5a. Manhacks: These could be stolen from raiding combine warehouses, or they could be taken from metropolice being killed before they have a chance to deploy their manhack. The light would be orange instead of red.

5b. Scanner: It's also feasible for scanners to be immobilized and disabled, before the rebels rewire and hack it to fit their own purpose. I imagine that taking pictures would be of very little use to the rebels, and I imagine that it would be retrofitted to become an explosive weapon. The scanner would look mangled as a result of rebels breaking it open and messing with the circuits, with exposed wires and dynamite visible on the outside. The scanner would ram into their enemy and explode, causing about the same amount of damage as a grenade. If combine shoot it down before it explodes, it will stop hurtling towards them and instead explode in the spot its currently in.

5c. Synth Scanner: Similar logic to the regular scanner. Although, this one would take photographs unlike the regular scanner, which would likely be uploaded to Kleiner's computer (lore only) for reconnaissance. It automatically deploys and drops mines, which are always targeted with rebels in mind, similar to if you picked it up with a gravity gun.

I also think it would be cool if there were other variants of Combine technology rebranded for rebel use, such as Striders and Hunters, but those seem like entirely individual beings with their own free will, albeit brainwashed, so I seriously doubt rebels would be able to repurpose them.