Currently on pre-order are the Soviet M3 Halftrack and Germany’s Sd.Kfz. 251 came out. Also, trucks such as Sd.Kfz.7, GAZ AAA and Stewbaker came out as regulars.
I agree with the addition of mechanized squads. It would have been right to add it at some point. However, please do not pay only for premium armored half-tracks, i.e. APCs.
Each country has developed different types of APCs. In the case of Germany, it is Sd.Kfz, the previous version of the premium version. 250, the US has the M3 Scout Kana M2 Halftrack, the USSR has the B-3 and Japan has the Ho-Ki.
These would fit next to the trucks in the research tree.