The driver and a passenger are both thought to have run away after the crash happened near the Junction 9 exit for Wednesbury in the early hours of Saturday morning.
The red Vauxhall they were in was the only car involved and was left destroyed.
Both the front and back windscreens were smashed, the bumper and bonnet were both removed and all of the driver's side of the car was crumpled.
Two lanes of the northbound motorway were shut as a result of the crash, which happened at around 12.30am.
Police officers, traffic officers and maintenance crews were sent to the scene where debris was scattered across the motorway.
National Highways said all lanes were back open at 4.30am.
A Central Motorway Policing Group spokesman said: "Two very lucky boys somehow walked away from this before we got there.
"If anyone recognises the car or knows about this, we’d like to check on the welfare of both."
A West Midlands Police spokesman confirmed that the people involved had not been found by Saturday lunchtime.