We spend lots of time concerning ourselves about the amounts of harmful carbon dioxide that our cars are emitting into the air outside, but we should be thinking about the harmful emissions inside as well. Here is an example of how the internal emissions from the interior of a car has caused its owner some grief. After forty-five minutes of sitting in the car, he was ready to fall asleep due to the carbon monoxide emissions from the various plastics and fabrics which made up the majority of the vehicle's interior.
According to this article, newer cars tend to be significantly worse than older ones. Additionally, the more expensive the car the less likely the materials are to make you feel sick. Other potential problem areas could even include child safety seats. Major organizations such as the EPA realize that there are potential risks inside cars, but there is currently no regulation on the issue. Manufacturers vary in their amount of concern on the issue, with Volvo taking it very seriously, Toyota working to reduce their chemical impact and Honda not being sure that there is a problem at all. Out best (and non-legally-binding) advice: let your nose be your guide.
[Source: Automotive Blogs, MSNBC]