I personally just make sure all the removable interior items and accesorries that came with the vehicle are present ansd that all the rubbish is removed from the interior, though its not much as I tend to keep the interior vehicle clean anyhow.
Exterior if its dirty its dirty I am not to bothered especially given how the weather can change so quickly and to be honest there’s nothing more a vehicle inspector likes more than a nice shiny vehicle to inspect as you can clearly see any scratches and dents etc.
The vehicle once handed over will be shipped to a refurb centre and washed and valated again so I dont really see the point in washing and cleaning it throughly before handing it back but each to there own.