If anybody happens to do any detailing as a business or just to help out a friend, always check inside of the vehicle before releasing it to the owner.
Another words, check & double check under the seats & engine compartment to see if you had left any cleaning items behind. Items such as brushes, bottles of cleaners & etc.
If a customer arrives to pick up his or her vehicle & sees something left behind, this is a sign of rush job with their vehicle & they will take it as a sign of weakness & will probably never be a returned customer.
I went to pick up a customers Porsche that was in a extensive rollover & opened the door to find out there was some rocker panels screws & misc. behind the seat. This was very hard to believe since the cost of damage to the vehicle was around $35,000.00. This car had some extensive work done to it to make it back into it's original condition.
With a price tag of this magnitude, you would think that every detail would be looked upon delivery to the customer. WRONG!, words of wisdom.