Used bait and they were all over it this morning. I thoroughly washed the roof and hood with soap and water. They were dirty and a little sticky. Ants seem to have disappeared. Also used a small amount of Raid in a couple of spots.
I believe this van was parked under some maple trees and the ants were hiding out when I drove it home. I found no nest. I took off the cover of the rooftop AC, expecting a nest and found nothing. Good chance there were only 100-200 ants total.
Just checked it and none in sight.