The police must be real softies around your way...
You were being chased by the police in your moms car, you crashed it... they caught you, drunk. You admitted everything... and now they haven't got enough evidence to carry the charge through court? Certain things are not adding up here.
failure to stop for the police is a crime.
dangerous driving is a crime.
drink driving is a crime.
driving without any documentation (insurance etc) is a civil offence for which the least you would get is a fine and a 12 month driving ban (even if you haven't got a license, lol). Unless you are already serving a driving ban, then it becomes a crime..
criminal damage is a crime.
Together they make quite a serious set of charges, all charges you admitted to in interview. Now they don't have the evidence to charge you? Also, if you are drunk then the police are not allowed to question you till the next morning, after you've sobered up.