Is there a reliable way to find out what factory options and trim features a vehicle actually has?

The listing description usually lists key options and trim level where available, and a vehicle history report (using the VIN) will often show the original build sheet, including factory-installed options. A Carfax-style report is generally better at showing title and accident history than a full options list, so for a definitive equipment list, decoding the VIN through the manufacturer or a VIN-decoder tool tends to be more accurate.