NEW YORK--(BUSINESS WIRE)--Fitch Ratings has assigned an 'AAAsf' rating to the class A notes of Ally Master Owner Trust (AMOT) series 2015-3. The Rating Outlook is Stable. KEY RATING DRIVERS Quality of Wholesale Receivables: The trust receivables backing this series have a high percentage of floorplan loans backing new vehicles (89.4%) and strong aging distribution, with only 4.7% of inventory aged past 270 days. The receivables are geographically diverse. Adequate Diversification: The top 20 d