The future of the diesel car will take another decisive turn on Thursday (22 February), as one of Germany's top courts could be set to impose a ban on the vehicles.
Germany, home to Volkswagen, the world's largest car manufacturer, could be set for a major shake-up if a ban on diesel cars is imposed.
The Federal Administrative Court in Leipzig will decide whether to ban diesel cars from major cities such as Munich, Stuttgart and Cologne as part of an ongoing bid to reduce emissions.
The ruling could have major implications for the wider car market not only across Germany but throughout Europe as nations try to meet strict EU emissions targets.
There are approximately 46 million cars in Germany with more than 15 million of these being run on diesel fuel.
Recent emission scandals and concerns for the environment have seen diesel car sales tumble across Europe.
According to Forbes, between 2011 and 2017, diesel car sales fell by around 10% across the continent.
In Germany, despite being the home to VW, Porsche, Mercedes and BMW, diesel sales in January 2018 were down by 12% compared to the same period in 2017.
The environmental group DUH, is suing the car manufacturers, in particular VW, over the levels of certain toxins being released into the atmosphere.
"The key question is whether bans can already be considered to be legal instruments," said Remo Klinger, a lawyer for DUH. "It's a completely open question of law."
The group says that in 90 German towns and cities, the levels of toxic particles exceeds the EU regulatory limits.
The court will deliberate on the matter on Thursday morning where a decision is expected to be announced shortly after.