The VW dealer tried this on my wife when she had her Jetta TDI, serviced at the dealership a couple of years ago. She called me and asked if she should get the fuel and emission system cleaned, per the service writes recommendations. I told her no way it was a waste of money, the service writer than asked to speak to me. He than tried to explained the so, called benefits to me, I again said no to him. He was not very pleased according to my wife when he got off the phone.
Whenever she took her car in for the annual service check up, the dealer was always pulling something on her to run up the bill. She now insets that I accompany her to the VW dealership when her car goes in for service. Her comment to me after our first time together was why didn't the dealer service writer try to add extra service to the car's maintenance. I said you need to ask the service writer that! I didn't want to tell her because she was a woman the service writer wanted to take advantage of her lack of knowledge of cars.
Attention: TDR Forum Junkies 
