The GL4 'Boar' armoured car went through a somewhat troubled development as designers had to engineer a vehicle with many requirements that contradicted each other at times. The core need for the GL4 was high road mobility and speed to make it an effective advance recon vehicle. Experience in 1342 showed that the GL3 Mongoose was poorly suited to street fighting and thus a requirement for the GL4 to be armoured against light AT guns and AT rifles was added. This costed too much in terms of weight and negatively effected its mobility the case of the XGL40 prototype.
There was also a persistent issue with armament, the 40mm wasn't well liked by the army. A 75mm howitzer was mounted on the XGL41 which was suited to anti-infantry engagements, and HEAT shells provided the needed penetration to deal with armoured targets, however the ammunition took up too much space in the tank and the gunner had trouble both loading and firing the gun. In 1343, the 25mm army variant of the naval AA gun had been battle tested and was found to be favorable against both infantry (due to its ROF and shell size) and against lightly armoured vehicles due to its HVAP shells. The 25mm was chosen as the armament of the Boar.
Further experience with the vehicle showed a vulnerable to mines and shaped charges, to combat this the Boar received side skirts and spaced sheets by 1346.