German automakers pledged Wednesday at a summit with political leaders to spend about 500 million euros (592 million dollars) on upgrading software in 5.3 million diesel cars, in an effort to cut emissions and restore confidence in the beleaguered industry, according to dpa. While the carmakers appeared to have temporarily headed off political pressure for more expensive changes to hardware, Environment Minister Barbara Hendricks insisted that software updates were only a first step towards improving air pollution levels. "Of course, today's result is not enough in the end," Hendricks told a press conference following the summit. Stephan Weil, the premier of the central German state of Lower Saxony, which is home to Volkswagen, said the push for hardware changes would continue. The carmakers attending the summit in Berlin - VW along with its luxury brands Audi and Porsche, BMW, Daimler, Ford's German operations and French-owned Opel - agreed to the upgrades as part of a series of measures to address the crisis facing the diesel vehicle manufacturers. The automotive industry was rocked in September 2015 when VW admitted to installing instruments that cheated diesel emissions tests in more than 11 million vehicles worldwide. The crisis deepened last month following media reports that five manufacturers - VW, Audi, Porsche, BMW and Daimler - had since the 1990s been members of a secret cartel whose operations included discussions on emission controls and standards. A survey by pollsters YouGov released on Wednesday found that only 41 per cent of Germans have confidence in the car industry, which employs about 828,000 workers, representing 14 per cent of the country's manufacturing-industry workforce. "The automotive industry is aware that it has lost a considerable amount of confidence," the German automotive industry association (VDA) said in a statement following the diesel summit. "We must and we will work to win back this trust," the VDA said. Upgrading the software is estimated to cost about 100 euros per vehicle, with VDA essentially saying that VW, BWW and Daimler would pick up the bill. The venue for Wednesday's meeting had to be switched at the last moment to the Interior Ministry from the Transport Ministry after environmental activists climbed onto the building's roof to hang a sign protesting threats to air pollution standards. The summit also formed part of the build-up to Germany's federal elections on September 24, with Chancellor Angela Merkel's Christian Democrats coming under fire for maintaining an overly cosy relationship with the powerful carmakers and for their handling of the emissions crisis. Munich-based BMW said owners of older generations of its diesel models will be offered a so-called environmental bonus of up to 2,000 euros if they trade their vehicles in for a new model that meets current standards. Daimler said improvements to about 1 million of its flagship Mercedes Benz diesel-powered cars would reduce vehicles' nitrogen oxide emissions by 25 to 30 per cent on average, which was the summit's aim. The Berlin meeting, which included the premiers of the five German states where the automakers are based, also agreed to the creation of a special 500-million-euro "sustainable mobility" fund to address urban pollution problems. The automakers are to join governments in contributing to the fund, the VDA said. The parties also agreed on the creation of a new subsidy programme aimed at the development and promotion of clean urban transport systems, such as cycling and rail, as well as bolstering public support for electric vehicles. Adding to the mounting pressure on the industry, a Stuttgart court ruled last week that diesel cars failing to meet emissions standards could be banned from the southern German city on certain days, possibly paving the way for other cities to follow suit. Britain and France have signalled their intention to ban the sale of new petrol- and diesel-powered vehicles by 2040 as part of an effort to promote electric vehicles.