"We believe our service measures can eliminate the unpleasant smell and rule out the possibility of peculiar smell from the carpets," the statement said.

If customers complain again after changing carpets, "we will take necessary measures based on specific conditions of each vehicle to solve the problems", according to the statement.

There is much discussion online about measures that could be taken to reduce or cover the stink. However, no one knows for sure where the smell comes from or what harmful elements it indicates.

The current dilemma for Chinese car owners is complicated by the lack of effective legislation concerning the air quality inside an automobile.

A guideline on evaluating air quality in cars has been in effect since March 2012. But it lacks legally binding force as it is only an industry standard, and meanwhile it targets mainly new vehicles.

Now, Sun's C200 spends most of the time in his garage.

He has his fingers crossed that media exposure around the International Day for Protecting Consumers' Rights can help.

"I hope the car can be recalled and given back to me as a really safe one," he says.