"He still has bumper marks on his forehead,'' Mieses' brother Ray Cepeda told ABC News.
The rest of the bikers then chased Lien's Range Rover up the West Side Highway and onto the Henry Hudson Parkway, where they bashed his car with their helmets, dragged Lien out of the vehicle and beat him.
The man being questioned by police is thought to be responsible for pulling the Range Rover's driver out of the vehicle, cops said.
The entire confrontation was captured on a six-minute helmet-cam video taken by one of the bikers and uploaded to the Internet.
Police are now combing through the video and witness accounts to find other suspects involved in the attack.
The NYPD distributed a still from the video of two suspects wanted in the assault on the driver and said that one bike had a flag sticker of Guyana on the back. The drivers are still being sought.
Police Commissioner Ray Kelly said Monday that the driver would not face charges for hitting bikers, including Mieses, as he fled.