My son 19 was arrested in missouir for DUI hit and run. What do I need to do and what is his chances on this?

The first thing you need to do is get him a criminal attorney.  DUI hit and run is a serious offens.  If you need help in finding a lawyer in your area go to www.AttorneyPages.com.  As to what his chances are several factors will be considered.  For example his age (he is an adult not minor),  what , if any, past record he does have?  (a good driving record and clean criminal past certrainly will be of help), the circumstances of his arrest? (did he eventually turn himself in or did the police have to track him down).  These are the things that your attorney will go over with you and your son.

Also, there may be civil liability as to the accident itself.  Just because there was only $2,000 of damage doesn't not mean that the occupants of the other car didn't suffer any injuries, even if they were not immediately apparent.  And if a DUI was involved your insurance may not cover you on these claims.

Good luck.