Ok, so I have a cali car duster, and my problem is that it leaves a film behind sometimes. I know its the parafan wax or whatever its called. I let the duster cure so I dont know what its doing this? Next question, when is it appropriate to do a spray detail on your car?

 

I'm not sure about the duster. I've never used one.

As for a "spray detail", I use Zaino's spray detailer once I'm finished washing the car, (keeps the dust off) and after I've gone for a ride, provided the car hasn't picked up alot of road grime, etc.

Other than that, I prefer to wash it.

 

Use the spray detailer to remove any grease streaks left from the duster.