The Mareșal never came to see action because its development and production were heavily slowed down by Anglo-American bombings and finally put to an end by the invading Red Army.

[4][5] The Mareșal's qualities included its strong firepower, accurate gun, good mobility and very low silhouette (around 1.5 m),[4][6] the latter of which would have made the vehicle a difficult-to-hit target for enemies.

[12][13] Car (definite article form carul) is, in this context, an outdated Romanian word for "tank", based on French char and Italian carro.

[25][26] A firing test showed that the T-34 was invulnerable to the R-2's 37 mm gun at any angle,[27] which led to said Romanian tank being given the new role of exclusively fighting unarmored Soviet positions.

This vehicle's characteristics were decided in January 1943: they included small dimensions, strong firepower, well-sloped armor and a maximum speed "higher than that of tanks".

Due to this lack of experience, they had decided to forgo theoretical preliminary plans and mate an artillery piece with an existing tank chassis, studying practical problems, which would eventually lead to a truly local design through continuous testing and modification.

In parallel, another model armed with a Katyusha rocket launcher was built for artillery purposes and tested in June and July, but this project was not continued either.

[32] As a result, a new model was built by a team consisting of engineers Captain Gheorghe Sâmbotin and Major Nicolae Anghel, who were tasked with designing a new vehicle appropriate for service on the Eastern Front.

Due to the exceptional performance of the Romanian anti-tank gun, Lieutenant-Colonel Paul Drăghiescu suggested that it should be mounted on future prototypes of the Mareșal.

[12] British author Mark Axworthy writes that the 75 mm Reșița M1943 was arguably the most versatile gun of its class during World War II, outperforming its Western, German and Soviet equivalents.

[51][52] Lieutenant-Colonel Haymann, an OKH delegate who attended M-04's testing, stated that the Mareșal is going to be effective against the Soviet army, calling it ein großer Hetzer, which can roughly be translated as "a big botherer" or "a bothersome enemy".

[3] Mark Axworthy and Walter Spielberger note how Hitler "was enthusiastic" about the Mareșal and agreed supporting its development, despite Germany having problems with its own armored fighting vehicle production.

During the bombardment, a guard soldier by the name of Turcescu-Cristea had left the bomb shelter and went into the targeted Mareșal's workshop, managing to put out the fire and save the production tools and archive room from total destruction, while getting hurt in the process.

[4][5] The later testing stages involving M-05 occurred in August and September 1944, in the immediate aftermath of King Michael's Coup, which overthrew the pro-Axis Antonescu and put Romania on the Allied side.

[68] The only known mention of the vehicle after this point is a report from 1 November 1944, which stated that the "M-project" — as the Mareșal was referred to — was not to fall out of interest, since its production was not out of question even after the end of the war.

Following the October 1943 testing of M-01, M-02 and M-03, Major Anghel and the director of the Rogifer Works were sent to tour several German factories to get information on the latest aspects of tank development.

[4][70] The Germans also offered to assist Romania by sending specialists to the Rogifer Works and supplying necessary components, including gun optics, armored plates, and radio sets.

[58][50] Apart from stopping Romania's need of having to get supplied with German tanks, another reason why Hitler had agreed with helping the program was a psychological oneː the vehicle's name.

[74] This fact had led to Hitler wanting to assist the Mareșal's development, since the vehicle was named after the Romanian leader, writes Walter Spielberger.

By the time the convention was finalized, the Germans were interested in ordering several dozen Mareșal chassis to mount 37 mm Rheinmetall anti-aircraft guns, and not only offered Romania full license manufacture of the Hetzer's 160 hp Praga engine for the Mareșal (the Western Allies had overrun the Hotchkiss plant), but also, because the two vehicles would then have a high commonality of parts (engine, radio, tracks and sights), offered a license for the entire vehicle.

[77][35] While in Germany, the Romanian commission responsible for the Mareșal had learned that the Germans were also studying the possibility of mounting a strong anti-tank gun on the Panzer 38(t) light tank chassis.

Discussions had led to the conclusion that the Romanians' design solution for the Mareșal was correct and that they were more advanced than the Germans in developing their light tank destroyer.

He told the Romanians how the Germans had been searching for solutions to design a light vehicle armed with a strong gun for two years, and continued by saying "we didn't find it, but you did".

Each of them was to fix problems shown by the previous prototype, gradually improving the Mareșal until it was to become a vehicle worthy of serial production and capable of effectively confronting Soviet armor.

They were wrong, but the trials did reveal a number of deficiencies, such as a failure of the bolts securing the gun mounting, track slippage, a rather weak engine and a cramped interior, among others.

[43][32] The "M" Staff, a special committee directly responsible to Antonescu's cabinet, was entrusted with the Mareșal project's supervision from August 1943, because production would require the involvement of an increasing variety of military and industrial agencies.

It was tested at Sudiți in early February 1944 in the presence of German Lieutenant-Colonels Ventz and Haymann (delegates of the Waffenamt and OKH, respectively), who were impressed by the mobility of the Mareșal and the viability of the novel design solution.

Romanian officials stated they will attempt materializing Ventz's proposal after testing a Soviet 45 mm gun's firepower at the Sudiți polygon.

M-04's frontal armor plate had an angle of 25°; its horizontal gun traverse was of 15°, which the two German officials described as "certainly sufficient" due to the ease of turning the vehicle; gun elevation was of -5°/+10°, also considered sufficient; the vehicle carried 45 rounds of ammunition; its speed, low profile and high shell velocity made it possible to fire at closer ranges and with more accuracy, lowering ammunition consumption.

They were largely Romanian-built, the main remaining foreign components having been the Hotchkiss engine and gear box, a new ČKD suspension, a German Telefunken U.K.W.E.e 10W radio and part of the sights.