The Secret of Selling

I may have accidentally stumbled upon the real secret of selling.
In the complex, verbose and sometimes deceptive arena of selling used vehicles - tonight I saw success. Yes, tonight I sold our old pickup. It has served us very well for many years and many miles (253,000 miles to be exact). I sincerely hope the new owner gets many more from it.
So, it took somewhere in the neighborhood of 4 - 6 minutes to make the sale. As the buyers got out of their car, they handed me the money (my full asking price, by the way). Then they asked to hear it run. We started it up, I handed them the title and they drove away.
Did I mention the temperature outside was about 9 degrees?
This tends to discourage protracted discussions and intensive examination of every square inch of the vehicle.
My best suggestion for all of you latent used car saleman out there is to bring the vehicle up to Wisconsin around December or January, Make sure you park it outside - out in the open where it's windy, if possible. Then, wait for a cold snap; single digits or sub-zero is even better. Next, bring on the buyers.
If you can't manage this scenario, then I would at least try to wait till it's pouring rain to show the car. The bonus is that it will look really shiny when it's wet.
Oh man, what am I saying? What have I become? Somebody stop me before I make a regrettable career move.