I have a 1999 Boxster and needed two new tires on the rear.  I ended up getting the Continental ContiSport Contact2.  Apparently on the front I have the Continental Conti Sport Contact.  There is a different tread pattern.  Do you all think that I am going to have any performance or handling issues?  
Fronts are 225/40-18 
Rears are 265/35-18
Your thoughts are appreciated!