I agree with everyone that handwashing is best if possible. There are a few things that can go wrong in a drive-thru setting that can potentially mess up your car. Do you have any good hand wash places where you live? I woud use them first and if that is not an option I would then use the touchless ones. It also depends on how obsessive you are about your car. Most people can use drive-thru's and never think twice about it. If you are asking the question, you may be more towards the obsessive side.

I have been forced to find alternatives to hand washing myself and it is driving me crazy. We are under fairly heavy water restrictions here is Georgia becasue of drought conditions. I have not been able to wash my car in my own driveway since last summer!