As with all sides of things there will always be different opinions and perceptions, i had 4 years of trouble free miles (about 50k milage) out of my zs before i decided to molest it.
I personally wont be selling mine unless unforseen circumstances dramatically change my life. eg i can no longer drive or i can't afford to even run one car.
I know i am a some-what special case with the amount spent on mine, but for me dont think you will find a car for as little money as most models sell for for that will not give you that simple driving pleasure - and each of the models do something slightly different too. so there are horses for coourses as it were
my plan for when mine becomes un-economical to keep on the road (who says it is not already
) is to strip it an take it even further on the tuning side of things. by that time i would have a big old barge to tow it and will store it off road etc.
I do however need to tighten my belt a bit as i am bout to move house so wont be able to just throw money at it anymore; so i am hoping that it's current strip down and rebuilt will be the last for a long while!