"Based on the information, there is a clear reduction in emissions," Hansen told Reuters.
"As a result, I'm facilitating meetings with the appropriate UK government agencies, as we want to ensure that British ownership and manufacturing is maintained."
The men are also in contact with car-makers Toyota Motor Corp of Japan and General Motors Corp. of the United States. Houston said they have also received substantial offers from two unnamed Asian companies.
Both Toyota and General Motors declined to comment.
SECRETS
If the system takes off, drivers with a Greenbox would replace it when they fill up their cars and it would go to a bioreactor to be emptied.
Through a chemical reaction, the captured gases from the box would be fed to algae, which would then be crushed to produce a bio-oil. This extract can be converted to produce a biodiesel almost identical to normal diesel.
This biodiesel can be fed back into a diesel engine, the emptied Greenbox can be affixed to the car and the cycle can begin again.
The process also yields methane gas and fertilizer, both of which can be captured separately. The algae required to capture all of Britain's auto emissions would take up around 1,000 acres (400 hectares).
The three estimate that 10 facilities could be built across the UK to handle the carbon dioxide from the nearly 30 million cars on British roads.
The inventors say they have spent nearly 170,000 pounds ($348,500) over two years developing the "three distinct technologies" involved and are hoping to secure more funding for health and safety testing.
Not surprisingly, the trio won't show anyone -- not even their wives -- what's inside the box.
After every demonstration they hide its individual components in various locations across North Wales and the technology is divided into three parts, with each inventor being custodian of one section.
"Our three minds hold the three keys and we can only unlock it together," said Houston.
