In service they proved to have some serious shortcomings. The engines were weak and did not allow the vehicle to fully exploit the abilities of the chassis, not even being able to cross the ditches at the sides of roads. The armor was thin and could be penetrated at close range by rifles and the ZB vz. 26 machine guns were not capable of sustained fire.
The Army decided to organize them in three-vehicle platoons assigned to the reconnaissance companies of the four Mobile (Rychlá) Divisions and assigned the extra platoons to support the border areas. These platoons were heavily used suppressing the protests and violence instigated by Konrad Henlein's Sudeten German Party (Sudetendeutsche Partei - SdP) and the Sudetendeutsche Freikorps (paramilitary groups trained in Germany by SS-instructors) between May and October 1938. After the Munich Agreement two companies of OA vz. 30s were sent to reinforce Slovakia and Ruthenia where they were used to repel Hungarian and Polish border-crossers, sometimes up to a battalion in strength. They helped to screen the infantry when they had to evacuate southern Slovakia after the First Vienna Award on 2 November 1938. Ten armored cars, no longer needed once that the border areas had been annexed by Germany and Hungary, were sold to the Gendarmerie in February—March 1939. Two companies defended Carpatho-Ukraine in March 1939 from a Hungarian attack, but were forced to seek refuge in Slovakia and Romania. One OA vz. 30 was captured by the Hungarians during the fighting, but they made no known use of it.
The Germans captured one OA vz. 30 in October 1938 that was being repaired in the Sudetenland when they occupied that area. Another twenty-three were seized in March 1939 when they occupied Bohemia-Moravia. Seven were used by the propaganda companies as radio cars. Ten were taken over by the Uniformed Police (Ordnungspolizei) and three equipped a platoon of the 14th Armored Police Company (Polizei-Panzer-Kompanie) in Slovenia in January 1944.
Ten armored cars were seized by the Slovaks when they declared independence in March 1939, but eight additional OA vz. 30s fell into their hands when Czech troops were sought refuge in Slovakia after fighting the Hungarians in Carpatho-Ukraine. One was destroyed during the Slovak-Hungarian War that began a week later. The seventeen surviving OA vz. 30s formed one company in the Armored Battalion "Martin" formed by the Slovak Army in mid-1939, but that was reduced to a platoon by late 1939. Four armored cars reinforced the 2nd Infantry Division during the invasion of Poland and three others reinforced a cavalry reconnaissance unit in the vicinity of Sanok. A company of six OA vz. 30s was part of Mobile Group Kalinciak that was formed on 5 September to work with the 2nd Infantry Division, but saw no combat before being withdrawn back to Slovakia on the 21st.
A platoon of three was assigned to the Mobile Group that joined the Germans in Operation Barbarossa on 24 June 1941. Two more were added when the Mobile Group was reinforced and redesignated as the Mobile Brigade on 8 July. The only serious combat encountered by the Slovak armor was at Lipovec in late July where they failed to dislodge the Soviet 44th Mountain Division from its positions. One OA vz. 30 was destroyed during this battle and two others were heavily damaged. All of the armored cars were withdrawn together with all the other armored vehicles and returned to Slovakia in early August. A company of six OA vz. 30s was sent to reinforce the Security Division on anti-partisan duties in Ukraine in August 1942. Two were destroyed in combat and there was only one running when the survivors were withdrawn back to Slovakia on 12 January 1943. Once the Panzerkampfwagen IIs that the Ministry of Defense had ordered to replace them arrived in January 1944 they were put into storage although they were still carried on the books. They saw some use by the insurgents when the Slovak National Uprising began in September 1944, but little is known of their activities.
Almost nothing is known about the career of the OA vz. 30 in Romania after one Czech company of nine sought refuge there in March 1939. One unconfirmed report says that some were on the strength of the Romanian dictator Antonescu's bodyguard unit (Batalionul de garda al maresalului Antonescu or Regimentul de garda al Conducatorului Statului). Supposedly three were destroyed during American bombing of Ploiesti in the summer of 1944 while being serviced at the depot there.