CBP Officers here were polite and friendly; if a little baffled when I rolled up in a Ford Puma on UK plates in 2016.
They got initially stuck logging the car into the country because they (understandably) only had codes for Canadian provinces & US states!
I had exited a week or so before on a J1 visa and was reentering in an ESTA (Visa Waiver).
With all paperwork in order for both the car and myself, CBP processed my visiting status and wished me safe onward travel.
I began filming my documentary here in Detroit MI continuing onto San Fransisco CA. See the episodes right here under the playlist:
The Lucky Black Cat
Thank you for watching.