In the United States, where authorities first exposed the wrongdoing, VW has already committed to pay $23 billion to aggrieved customers to settle lawsuits in addition to repairing the vehicles.
The Dieselgate scandal blew open when Volkswagen admitted in September 2015 that it installed software devices in 11 million diesel-engine cars worldwide that reduced emissions of harmful nitrogen oxides when it detected the vehicle was undergoing tests.
The EU lacks the authority to fight VW. Day-to day regulation of the auto sector, including approving new car models for the road, remains under the authority of national governments.
Other barriers include a political reluctance in car-making countries to punish an industry that has put such a high percentage of diesel-powered vehicles on European roads.
Manufacturing diesel cars helps employ millions of workers across Europe - either directly or indirectly.
According to EU data, the auto industry employs a total 12 million people in Europe and accounts for 4.0 percent of the bloc's gross domestic product.
"We have spoken a great deal on the issue," lamented Julie Poliscanova, an activist with Transport & Environment, a Brussels-based non-governmental organisation.
"But if you look for detail and concrete actions, unfortunately Europe has not made much progress," she added.
Indeed, the European Commission, the executive of the 28-nation bloc, appears helpless against Volkswagen even after more than eight million of its incriminating vehicles made it to European roads.
Vera Jourova, the commissioner for consumer affairs, has been pleading with the German automaker to offer compensation to its European customers, but so far without success.
In many EU nations, consumers have no recourse to US-style class-action lawsuits and face weaker rules on defeat devices.
The strength of the Americans is "they have rules and they enforce them," according to Christine Revault D'Allonnes, a socialist member of the European Parliament who serves on a committee investigating emissions from diesel engines.
The final version of a report from the committee will be voted in the parliament in April.
A draft denounces the "bad management" of the commission and the member states which allowed automakers to justify a long list of exceptions and loopholes when being checked for pollutants.
But as far back as 2013, the commission's research unit noted discrepancies in emission testing results depending on whether they were done on laboratory simulators or on the road.
While the EU acknowledged that this indicated the possible use of illegal defeat devices, Brussels did nothing.
After the scandal, the EU executive proposed new procedures closer in line with real world driving, which are to be launched in September this year.
But EU officials are despairing over the failure to make headway with a proposal to centralise car-type approvals in Europe.
"I see no shift of attitude in the industry, but (neither from) member state authorities for that matter," industry commissioner Elzbieta Bienkowska said this past week.
In December the Commission launched legal action against authorities in seven EU countries, including Germany and Luxembourg, for failing to crack down on emissions cheating.
The Commission is also pushing to obtain powers of imposing penalties and monitoring both the industry and national authorities who carry out tests.
"The idea that diesel is clean seems to have disappeared from public discourse," Poliscanova said.
Karima Delli, a Greens party member of the European parliament, welcomed the fact that Paris prosecutors have opened a probe into Renault over possible emissions cheating because the consequences cause harm to the general
"Will there be condemnation for automakers who not only harm the environment but also people? That's revolutionary," she said.
Researchers at NGO T&E estimated at 29 million the number of polluting vehicles on EU roads, contributing to 72,000 premature deaths a year linked to azote dioxyde.
In 2016, based on figures from the European Automobile Manufacturers' Association, the share of diesel in western Europe has declined slightly from 51.6 percent to 49.5 percent for new registrations.
The ACEA president said European buyers had largely overlooked the scandal.
In fact, the large-scale presence of diesel on European roads certainly makes "much more difficult politically to have a European response," Poliscanova said.