Arizona - easiest place to return vehicle permit?

thanks briansue!

Canadian Rainbirds wrote:
And from Nogales, its about 21 Km south of the border crossing.

thanks - except for Nogales crossing, can I expect the return banjercitos to be right at the border? I found lists online of crossings that can handle permits - & noticed that Nogales was the only one noted as " at km 21".