Texas Transportation Code - TRANSP § 503.039. Public Motor Vehicle Auctions

(a) A motor vehicle may not be the subject of a subsequent sale at a public auction by a holder of a dealer's general distinguishing number unless equitable or legal title has passed to the selling dealer before the transfer of title to the subsequent buyer.

(b) The holder of a dealer's general distinguishing number who sells a motor vehicle at a public auction must transfer the certificate of title for that vehicle to the buyer before the 21st day after the date of the sale.