You really care what anyone else thinks, let alone an 11 year old?
Do you enjoy the car? Enough said.
But if you still feel the need to respond take him for a "ride". That way he can find out just how much one of the best handling production sports cars in the world "sucks".
In addition, should you feel the need to further stroke your ego, any of the following articles are also good places to direct people:
http://www.thetruthaboutcars.com/?p=1304
http://www.thetruthaboutcars.com/?p=729
http://www.forbesautos.com/reviews/2005/porsche/boxster/testdrive.html