I reckon that "2 years life reduction" bit must be rubbish, put in just to generate some sort of discussion... which it has!
But I would think the value of the car would be reduced by track usage. Used value of a car is determined by nothing other than the market, i.e by the amount most people are willing to pay for any particular vehicle.
Joe public
perceives that track use must knacker a car, so they are willing to pay less. Joe public often doesn't know what he's talking about, but that's irrelevant in determining the used price of your car....
Pete