When we process a transaction as a dealer we don't retitle the vehicle in our name nor do we report the transaction. We reassign the title to the new owner and the purchase is reported when the DMV issues a new title to the buyer. If a Carfax or AutoCheck report is pulled after the transaction is completed, we do not appear as an additional owner or as the seller when the vehicle was sold.
In rare cases, we do retitle vehicles in our name if it helps the buyer register the vehicle more easily. We might do this if the seller's ownership is complicated, e.g. a death certificate is required, or if the vehicle doesn't have a title due its age. Our brief ownership will show up on a Carfax, but shouldn't be counted towards the total number of owners since we quickly sell the vehicle to the buyer as a dealer.