Nothing.
I have now talked three other people into buying a ZX2. This car sells itself. Awesome performer, simple design, and good quality. The interior needs some work but that doesn't bother me at all. It's different, not many have them (unlike the Civic).
To be honest I know more people with zx2 then with civics's. I had one before the car I have now (a 93 si prelude) and I have never seen a zx2 that holds a candle to my prelude. I can can blow away v8 jeeps and mustangs with my prelude, a feat inconceivable with a zx2. the prelude's non vtec 160 hp blows that little 2.2 in a zx2 away. and is more stable cruising at triple digits then a zx2 at 90. all around I would take a Honda over a ford any day.