The contact owns a 2015 BMW X3. The contact received notification of NHTSA Campaign Number: 24V608000 (Engine and Engine Cooling, Electrical System); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact stated that while driving at approximately 30 MPH, there was a burning odor coming through the vents on the dashboard. The contact stated that she had not observed any warning lights being illuminated. The contact stated that the odor was intermittent but had been occurring for almost 4 months. The contact had stopped driving the vehicle out of concern that the vehicle might catch on fire. The dealer and the manufacturer were contacted. The contact was advised by the dealer that a second letter would be sent when parts were available for the recall repair. The failure mileage was approximately 50,000. VIN tool confirms parts not available.