's motor vehicle production was based on use of domestic parts like components and mechanicals sourced from other Romanian manufacturers like ARO, Brasov, DAC, and SR.

In 1956, the first bus was built on a truck frame, and in 1957 the production program was enlarged also for trolleybuses, mini-buses and pick-ups made after T.V.

Beginning with 1968, Rocar started exporting vehicles in Eastern Europe, Africa, South America and Middle East and, in 1971, it bought a license from MAN, Germany.

Until the 1990s, "Autobuzul" made exports to Bulgaria, Hungary, Soviet Union (later Ukraine), East Germany, Madagascar, Benin, Burundi, Iraq, Colombia, USA.

[3] During the 1990s, ROCAR lost most of its customers (urban transport companies), mainly because of the old technology which led to low quality, low production capacity, and high prices – therefore many of their former customers bought second-hand buses and trolleybuses from the west, causing ROCAR high losses around the turn of the millennium until 2002 when it went bankrupt.

However, the contract with RATB and Bucharest local Council did not improve the deteriorating situation of ROCAR of the mid to late '90s, because other public transport companies (and other customers like The Army or Interurban Transport Operators) in Romania completely refused to buy its products (main reason stated by them being the low quality products, prices are too high, low availability due to low production capacities, outdated, and they were acquiring instead second hand or other new vehicles mostly (except for The Army, which were buying GRIVBUS or other new vehicles).

Although Rocar De Simon U412 was a fairly modern vehicle with EURO 2 engine and automatic transmission, and chopper in case of some trolleybuses it did not prove a very big success, as many other transport companies still preferred second hand buses/trolleybuses or other new buses/trolleybuses (MAN, Mercedes, MAZ, Ikarus, BMC), accentuating the deteriorating situation of ROCAR.

However, in the past, many other well known manufacturers (like Scania, DAF, Renault, Volvo, Mercedes, even MAZ (they wanted a partnership with ROCAR in mid to late 2000, just like the one with De Simon, to assemble busses as CKD delivered by MAZ, models 103, 104, 105,107 were proposed)) wanted to buy ROCAR or wanted partnership with ROCAR for assembling buses, trolleybuses and light commercial vans, but eventually gave up, and after 2000, no company showed any interest.

In the early 2003, while ROCAR was in its last days of life they made some repairs and reconditioning to some old buses belonging to the army and some other bigger companies (like Dacia), however no new demands were registered, and losses increased.

In late 2003 and early 2004, the company was liquidated and removed from the registry of commerce, ending 52 years of bus manufacturing in Romania.