Armoured cars were useful in Western Europe where there were massive road networks but they had poor cross country performance and so struggled in the east. Eventually the BAs were replaced by T60/70 tanks in the heavy scout car role.
BA armoured cars fought in the Spanish Civil War, Khalkhyn Gol, The Winter war and Barbarossa. Thousands were made.
The Germans even used a Spanish-made copy on the Eastern Front Spanish, which is a nice unusual modelling subject.
The cars were heavily armed with the same turret and armament as the T26 and BT tanks but had paper thin armour.
This resin and metal model is made by Warlord Games and I heartily recommend it. I left off the side steps because they are just where you inevitably grip the model and keep falling off. The real cars seem to have had the same problem, going by the photographic evidence.