I will start a with few:
BRDM-2 Azerbaijan ZKDM armed with 7.62mm, 30 mm AGS-17, twin 23mm cannons, four 57 or 80 mm rocket launchers and two smoke grenade launchers mounted on each side of the vehicle, which is a massive upgrade on the original model.
BRDM-2 gurcu Azerbaijan anti air armed with 23mm cannon and 7.62mm.
BRDM-2 Afghanistan upgrade with 57 mm rocket pod originally for a helicopter or aircraft.
BRDM-2 with BM-14-16 believed to be Afghanistan upgrade.
BRDM-2 Turkish upgrade with OMTAS anti tank missile system.
BRDM-2 with TOW missile system.
BRDM-2 Belarus upgrade Caiman
BTR-70M Azerbaijan upgrade with 23mm gun, and 7.62mm
BTR-50S Serbian upgrade armed with 30mm canon, 7.62mm, two 9M14 Malyutka(AT-3).
PT-76E Russian upgrade with a 57mm gun instead of the 76mm gun.