KAREN NELSON MOORE, Circuit Judge. In this diversity-of-citizenship lawsuit arising under the Tennessee Products Liability Act (“TPLA”), the district court granted summary judgment to Defendant-Appellee American Honda Motor Company (“Honda”) after considering several unsworn letters from various experts for Honda. Because our case law clearly prohibits considering such materials, and because Plaintiff-Appellant Shelly Sigler (“Sigler”) presented sufficient evidence to establish the existence of genuine issues of material fact regarding whether the airbag in her vehicle was defective and caused her injuries, we REVERSE the district court’s judgment and REMAND to the district court for further proceedings consistent with this opinion.

SUTTON, Circuit Judge. After the United States Tax Court concluded that it lacked jurisdiction over William and Carol Mobley’s petition, it declined to transfer the case to a federal district court under 28 U.S.C. § 1631. Because the Mobleys do not challenge the Tax Court’s jurisdictional ruling and because the Tax Court correctly concluded that it lacked authority to transfer the case under § 1631, we affirm.