That would have to be a multiple BP double blind study to confirm anything concrete.
If there was a case or even a few that linked a car rides to resumed feeding in BP's that were refusing food and restarted because of those rides would be something rare and incredible. I think the example given may have been related to a few animals and perhaps just luck. Car rides are not a desired option to induce a feeding response.
The species refuses food and eats when it is ready.
An established royal not eating is very much the norm.