I have made cases -
ID 17458492511
ID 17230450031
ID 17317800221
Thousands of dollars of our items MIA and the answer is always for us to show proof of ownership. We can only order X amount of an item a day, some are for us to send to FBA, some are to keep in the shop here at our dealership. When we have shown proof of ownership in the past, it seemed Amazon did not understand how to even read our invoices.
I am assuming you are ordering directly from Toyota or the manufacturer? You might be missing a Letter of Authorization giving permission to sell the brand's products specifically on Amazon. It will reject invoices without an LoA and I have seen them be rejected with the same generic responses as improper invoices, which really doesn't tell sellers what the issue is.