I have a vehicle that I keep changing to NEW in VinMotion, but the next day it�s always USED again. Why is this happening?

The vehicle overrides that apply to New, Used, and Certified are labeled Condition and Certification. (The Status overrides just update Active vs Sold.) Condition and Certification have to be set to the same source for them to apply correctly. This is because warranties are used to indicate New/Used/Certified in the feeds and elsewhere in the system. If Condition and Certification are being updated by AutoStik or Polling (as Primary), then the Primary source should be used to make the update.