Question juridique clé
Whether the cantonal court arbitrarily assessed the evidence on the determinant document for the authority discount.
Solution extraite
No arbitrariness was shown; the finding that the sales contract, not only the vehicle registration, was decisive for the authority discount was sufficiently reasoned.
Motifs extraits
The appellant failed to show that the court's reliance on witness statements, the internal regulation, and the commercial practice was manifestly untenable.