Again -- know your audience

I went to the auto parts store to get a new headlight bulb for the 2004 minivan and windshield wiper blades for the 1996 Camry. 

[This is the exactly the glamorous life I dreamed of as a child.]

While there the very nice young man at the desk kindly looked up the right parts and even installed the headlight bulb for me.  Thanks Mark. 

Then he tried to up-sell me as I paid him. 

Apparently I needed a "motor treatment"  to keep my car "running longer".

He thought it was a mistake not to use one.  I'd get longer life out of my car by using "blah blah blah."

I'm really not sure how much longer I can expect my 18 year old car to run. 

Know your audience man, a woman buying wiper blades for a 1996 Camry is already pretty good at keeping her car "running longer".... A motor treatment might be overkill. 

[And frankly I'm not sure I want my 18 year old car to run that much longer.  While I will never regret living debt free, I'm a little tired of the car.  I've never even lived in the same place for more than 12 years.  I re-arrange all of the furniture regularly.  It's hard to do that in a Toyota Camry.]