Commodores can be detailed anytime of the day or night, here's the tools you'll be needing;
Ok in all seriousness, you can detail a car the day (or week) beforehand then just keep them/it undercover until the day they're needed.
Or if undercover parking isnt an option, get them detailed the day before, then at 7am have someone out there giving them both an easy normal wash with a hose and a bucket just on the outside (get the morning dew off them) and leave time so they can dry in all the spaces like door jams etc. And of course, whoever does it in the morning has to do a decent job with a chamois
You know how long a full detail takes, right?