Yup. Pretty outrageous. I don't think it is custom's place to decide if the owner is gong to drive it on the public roads or only on the track. That should be up to the state Motor Vehicle Departments whether to grant it roadworthiness certs and license plates, or not.
He should have been able to import it and at least sit it in his driveway, or take it to the track, even if he can't drive it to work. There are plenty of purpose-built racecars that are street-illegal; they get towed to the track and have fun.
Now, if he'd filled out the paperwork stating it was a road car, then likely US DOT rules came into play, but still, seems not the place of customs to enforce since there are legal options.
