Nothing.
This is an excellent car with excellent handling characteristics. It is very much on par with my 1982 BMW 528e and understand why one reviewer called it the modern day BMW 2002.
I was concerned with going to a smaller car since I usually take long roadtrips with friends, although they find it every bit as comfortable as my old Saab 9000. The drivers seat is very comfortable with excellent adjustment mechanisms.
My only gripe with the car was that it lacks a little low end torque, but otherwise the Elantra is fantastic.
Handles well after you get rid of the factory tyres. It's a modern day Datsun 510!