Richard Usher, founder Ambergate’s Great British Car Journey museum, is shown here with the 1996 Land Rover Defender 90 driven by Brenda Blethyn in the ITV drama Vera.

When his parents, Scott (Zachary Levi) and Teresa (Meghann Fahy), learn that Austin is both autistic and has brittle bone disease, they initially worry for their son’s future. But with Scott’s growing ...