Groundcars are the TL3 analogs of the vehicles commonly in use on 21st-century Earth, allowing for some minor variations in electronics and capabilities. Primitive buggies of various kinds are found even on higher-tech worlds, thanks to their ease of construction and maintenance compared to the delicate gravitics of more modern vehicles.
Vehicle Weaponry
Most vehicles larger than a motorcycle or hovercycle can mount some kind of integral weapon. Groundcars can mount one weapon.
Heavy weapons take up more space than ordinary ranged weapons, and each such system takes up the space of two lesser guns. (Not possible on groundcars)