This article talks a little bit about "the rule of two" in New York State traffic law. This might be one reason why Jason would not be prosecuted for killing Danny,
Here is an article about the differences between murder and manslaughter. This can show nuances of also why Jason may not have been convicted of a crime. About half way through the page, there is an example of an event where someone kills another person with a car.
https://www.nolo.com/legal-encyclopedia/homicide-murder-manslaughter-32637-2.html
In terms of age and being prosecuted for a crime, this news article talks about how 16 and 17 year olds were automatically tried as adults (until changes that happened in 2017).
Here is a PDF about the housing bubble that burst in 2006. This greatly affects how Becca and Howie deal with selling their house.