When I unlock my car with the key remote or even when I manually unlock it, I get a loud ticking sound coming from the dash, and it stops after driving for a few minutes.
My car has 73000 miles.
My car has an automatic transmission.
This is a notorious issue with this model of Impala. The noise you are hearing is most likely the blend door actuator attempting to move to its default position but is not able to do so. This repair usually requires the blend door actuator to be replaced. This is often times a very costly repair as the dash sometimes needs to be removed from the vehicle in order to access the blend door actuator. If this repair is to be done, I would strongly recommend having the repair done by a qualified professional.