Thank you for your attention to this!
This is the first year I've used TurboTax for my 1120S; always hired CPAs in the past. They would always file form 4562, sometimes with mileage and sometimes not, but always filled in line 26, even after fully depreciated.
As you suggested, I've entered the mileage in Section B. Not sure if I should note the vehicle on line 26 or not, but I think I'll leave it blank since TurboTax didn't list the vehicle there.
