Blood was left covering the pavement after the gunfire in Oldbury on Saturday night.
Both cars had left when police arrived at the scene in St Johns Road just after 7.30pm but the injured 20-year-old man turned up in hospital a short time later.
West Midlands Police said the man's injuries had been "potentially life-threatening" but that he is now in a stable condition and has spoken to officers.
The area was taped off and blue tents were erected in order to preserve evidence, with forensic officers continuing their examination of the scene today.
House-to-house and CCTV enquiries are taking place and anyone with information about what happened is being urged to get in touch with the force.
Detective Inspector Ade George said: "We’re making good progress with the investigation, but it’s still in the early stages and we’re keeping an open mind regarding the circumstances and motive.
"I’d like to reassure the local community that we’ll be working all hours to find out what happened. Our priority is to find out who is responsible and take the appropriate action to bring them to justice."
Anyone with information can contact West Midlands Police via live chat at www.west-midlands.police.uk between 8am and midnight, or call 101 anytime quoting log number 3580 of 13/06/20.
Alternatively call Crimestoppers anonymously on 0800 555 111.