Ah yes, my highest part count and most detailed build so far.

Some "roleplay" information:

The M18 Marcher MGS was created out of a need for the Kerzian Marine Corps for a lightweight, airdroppable armored car capable of providing direct fire support to the infantry it is usually paradropped alongside.

ARMOR & SURVIVABILITY

The M18 has 4 crew members; gunner, loader, driver, and commander, and is armored with aluminium alloy and steel plates, providing all-around protection against 14.5mm HMG fire and up to 23mm APDS from the front. An optional armor package - which can be airdropped alongside it to equip it in the field in under an hour - outfits it with explosive reactive armor, slat armor, and both a hard-kill and a soft-kill active protection system for both passive and active defense against shoulder-fired RPGs and HEAT shells.

The M18 is equipped with laser warning receivers without modifications, to warn the crew when the vehicle is being painted by a laser rangefinder or a laser-guided missile.

The M18 is also outfitted with a snorkel to allow for fording of shallow lakes.

FIREPOWER

The primary aspect of the M18 Mobile Gun System: the firepower. It is armed with a 105mm smoothbore main gun with a bore evacuator, capable of firing a variety of rounds, although most commonly loaded with APFSDS-T, which is capable of penetrating ~300mm RHA@ 2 km@ 60 degrees, providing infantry with quite the punch, and HEATFS-T with a proximity fuse for use against helicopters or a regular fuse for use against ground vehicles.

The M18 is equipped with several optics on the turret, with night vision capability, and a 2nd generation thermal sight mounted on the rear section of the gun barrel, capable of spotting targets in low-light conditions at long ranges, while remaining relatively inexpensive.

The M18 has two machine guns, one's a 12.7mm M4 for the commander, and one's a 7.62mm M480B for the loader, while the gunner has a coaxial 7.62mm M480C right next to the gun for anti-infantry roles.

MOBILITY

The M18 is powered by a longitudinally-mounted 300 HP turbodiesel V8 engine, and is capable of traveling at a top speed of 104 km/h, thanks to its relatively light weight of ~18 tons, with a power-to-weight ratio of approximately 16.6 hp/t. Acceleration is somewhat quick, but not exactly stellar, as it is an armored car after all.

It is capable of traversing different types of terrain, and fares very well off-road thanks to its six powered wheels and per-wheel independent suspension.

CONCLUSION

All in all, the M18 is a rather inexpensive tool that excels in its intended duty, only coming in at about $1 million KRD (roughly equivalent to USD) per unit. It had performed admirably in the 1991 Golf War, the 2003 invasion of Heraq, and Operation Acquired Result.

(The history stuff is mostly a play on real history but with a fictional vehicle, so don't take it too seriously :p)