If courts do have a prudential power to discern real parties in interest, such a power would be inapposite here, as the plaintiff who used an LLC to purchase a vehicle, and the LLC assigned the right of action to the plaintiff after the commencement of suit.
Absent an equitable "lemon law" showing to the contrary, repairs on a vehicle owned by an LLC and therefore excluded from warrantied repairs did not effect an intentional relinquishment of a known right by the manufacturer that would allow a subsequent claim against the warranty by the LLC.
http://media.ca7.uscourts.gov/cgi-bin/rssExec.pl?Submit=Display&Path=Y2018/D07-11/C:17-2285:J:Hamilton:autcon:T:fnOp:N:2184815:S:0
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.