Here in New Jersey a new car does not have to be inspected until it is four years old (not sure about people coming into the state with cars under four years old), then it has to be inspected every two years. It is done by State Inspectors, so there is no charge, and no mechanics looking for things to find wrong, but you can wait in line for a long time. Personally I think the longest I have sat in an inspection line was about an hour and 20 minutes, but you hear some stories of two hour or more waiting times.