If you can afford to "enjoy" your car then all good. If you are spending alot of your spare cash and its leaving you short to buy other things then there is nothing wrong with selling it.
I sold my last ZT as it was a tad too big and wanted something a bit newer. Money is hard to come by and spending it on a car that is going to take most of your spare money up is not practical. You can still come on here and have a natter!
Since I sold my ZT Ive owned
A 2006 BMW 3.20d SE
2007 BMW 320d M Sport 163
2010 BMW 320D M Sport 172
2009 Ford Focus ST 225 (Bluefinned to 272 bhp)
And now drive a 2012 Golf GTD DSG 170 soon to be put up for sale as I have just purchased a 2013 Berlingo van with air con, parking sensors and bluetooth.
Needs must as they say. I still love to see the cars on here!