Deathwisher, I think you completely missed he point.
In CT, MT, and TNE, the functional designation APC is, like in the US military, a fairly narrow range. Current production in the US military includes NO designated APC's; it instead has IFV's. USArmy C&GSC had an excellent discussion of thee differences on their web site for a while...
The APC/Battle taxi, versus the IFV, versus the mounted infantry combat platform versus scout vehicle versus troop transportin light tank dillema has raged for years.
Functionally, for US Army designation, the APC was an armored cargo box with treads; many varints were armed, but the base M113 had neither firing ports for the troops aboard nor any antivehicular weapons, and could stop small arms fire. Later variants added firing ports, anti-tank weapons, artillery pieces, and other variants, but the base M113 is the "archetypical APC," a box made of armor that is self propelled, and designed to carry infantry to/from a battlefield, allowing them to dismount and fight afoot.
In traveller, APC's are uniformly better armored than GCarriers of similar Tech and home "nation".
GCarriers can be penetrated by the beter small arms of the traveller universe. APC's ususally can not. This based upon striker and MT result probabilities.
The MICV and IFV concepts do not actively appear in either striker nor MT. (in short, there is no rule about firing ports.)
These concepts, in a nutshell:
IFV: firing ports for mounted infantry to fire from, and light anti-tank weaponry on the mount: Fights in as a very light tank, with extra anti-personell capability; deposits the infantry, who fight dismounted; evacs them after mission fail or success; fights beside them when practical. The bradly is the protype IFV.
MICV: An IFV where the infantry are never expected to fight dismounted, and their small arms fire is demountable soley for non-vehicle capable sub-missions (like building clearance). None have been built by the US, as the role is really that of Anti-personell armored vehicle; south afric deployed some for internal peacekeeping in the 1990's; they were used by police. Several other southern African nations have deployed variations on this theme, some for SWAT team ops, others for anti-riot duty. One nation's used flamethrowers.
Also, just because it has armor does not mke it, to the military mind, an "Armored Vehicle". Essentially, Armored Vehicle implies immunity to slug-throwing small arms. The hummmer,despite it having light armor, really is not an APC, nor an IFV.
A lot of light vehicles mount what could be considered "light armor" (in fact, most bodies are as tough as medaevil plate), bu I doubt you;d consider a Dodge Ram an Armored Vehicle.