When cleaning carpets and upholstery, start with the driver's area first. It is then more likely that this area will be dry when the customer takes possession of the vehicle.
Clean windows after cleaning everything else inside, thus preventing soiling of the windows while doing the dirty work of cleaning door panels and headliners, et cetera. Do your interior dressing and conditioning after window cleaning so as to avoid tracking dressing onto the windows while wiping them.
When cleaning windows, first lower the windows slightly and clean the top edge of the window pane. Then fully close and clean the remainder of the window.
Be careful not to get any of your favorite interior cleaner on the clear plastic panel that cover the instrument panels. These cleaners can spot or fog the plastic.
In heavy carpet soiling situations or if there has been a spill between the seats, it is often easier to remove the seat completely from the vehicle, allowing excellent access to the soiled area for more thorough cleaning. I have found that, especially in neglected interiors, the time it takes to remove the driver and passenger seats is easily made up by the ease of access to the interior of the vehicle during the heavy cleaning that is necessary in these situations.
Be careful to check for wire harnesses under the seat. These usually come out of the carpeting directly under the seat and simply unplug.
Of course, be sure to re-plug the harnesses and securely re-tighten the seat upon re-installation.
Always rinse mats, carpeting, and upholstery after cleaning them to remove any cleaner residue. This residue will simply attract more dirt if left in the material. That is, the material will stay cleaner longer if rinsed.
Sourece: Automotive Detailing