VISMOD - Short for Visual Modification.
The National Training Center - Ft. Irwin, CA - the home of NTC.
If you want to see some serious modeling on a large scale, this is the place. The NTC is the home of the 60th Guard Motorized Rifle Division, which is actually the 11th ACR. Their job is to train incoming units by taking on the role of the OPFOR (Opposing Forces). The OPFOR takes on the tactics and equipment based on (in the past) a Soviet Motorized Rifle Division.
To create a sense of realism, the Army had to take vehicles in it’s currrent inventory and add VISMOD kits. The VISMOD kits consisted of metal frames supporting fiberglass panels. The panels were assembled/molded to represent the outside of various Soviet vehicles. While not a perfect representation, it was quite effective. Some visual aspects had to be sacrificed for functional and safety requirements. These kits were added to a couple hundred vehicles. Mostly aging M551 Sheridans, HMMWV’s, and modified M113’s.
Here is some information on the various assortment of vehicles which are currently being used by the OPFOR. A few of these are the real deal, while many of them are current US Army vehicles, with VISMOD kits added to visually represent some of the threats that a real unit would face in today’s world.

T-80 VISMOD M551 Sheridan.

BMP-1 VISMOD M551 Sheridan.

BMP-2 (OSV)
The OSV is an M113A3 chassis outfitted with a modified M2 Bradley turret. The vehicle has a visually modified exterior that gives it the appearance of a Boyevaya Mashina Pyekhoty-2 Infantry Fighting Vehicle.
…
The cost to operate and support an OSV is approximately 50 percent less when compared to the M551 Sheridan. Based on the high training operational tempo at the NTC, which is approximately 3,000 miles per year per vehicle over the course of 10 rotations, this will generate a high cost savings for the Army in the years to come. – excerpt from the linked site.

BRDM-2 RKH VISMOD HMMWV.
BTW…They even had a couple of UH-1’s which were had VISMOD kits added to represent Soviet HIND D helicopters.
Additional 2/11 ACR Photographs (OPFOR)
Armor In Action: NTC
History of the Opposing Force at NTC – Red Thrust Star, Oct 1994
I was stationed there from 1991-1995, as a member of Bayonet Recon (2/11 ACR Scout Platoon), part of the reconnaissance element for the OPFOR. Our vehicle numbers were the 610 series. [8D]