Deputies found father and son in a Toyota in a ditch in Orion Township.
The 44-year-old man was in town from Kansas. He had taken the boy and two 16-year-old girls out to dinner at Great Lakes Crossing and then drove north.
"He stops, gets some liquor, some hard cider, Crown Royal, they go into the hotel room, they all drink," said Oakland County Undersheriff Mike McCabe.
That was at the Palace Inn in Orion Township. Investigators say the man made a sexual advance at one of the girls.
"She kicks him out of the way and runs out of the hotel room. Shortly after that he flees the scene with his son," said McCabe.
He said the man's blood alcohol level was .28 as he drove onto M-24. The temperature was -3 degrees.
"No shoes. No shirt, no coat," said McCabe.
He rear ended another car at a red light on M-24, kept going and veered into the ditch. Emergency responders smelled alcohol on the boy.
"He blew a .13, which is .5 over the legal limit and he's 13 years old," said McCabe.
So he blew his own age. He complained of chest pains after the crash but did not have to go to the hospital. He is back with his mother.
His father faces charges and will be arraigned on Friday.