Nothing, brand new.
I rented this car while mine was in for repairs.
The SX4 is a well-built car. The fit and finish are quite good, but I would say slightly below the other mainstream Japanese competitors.
The cabin is spacious for a smaller car and the seats are comfortable.
However, I found that the brakes are way too touchy, just a little pressure on the pedal is enough to slam on the brakes, though admittedly, I got used to them enough that it became less of an issue.
My biggest gripe with the SX4 would be with the CVT. When taking off from a standstill, it starts off in low gear, but unless you really lay into the gas, it goes straight to its top gear ratio, and bogs the engine right down. The sound it makes is comparable to that of a manual transmission in 5th gear when trying accelerate from 30km/h. Very strange. So you have to press harder on the accelerator, which then puts it back in low gear and the car suddenly lurches forward... a little bit scary.
That being said, the CVT also has a manumatic-type mode, with six ratios. This eliminated the aforementioned bogging, and actually made the car go quite well.
All in all though, it's quite a nice package, but if I were to buy one, I would get a manual transmission one, since I was not a fan of the CVT.
In the UK we have the ordinary torque-converter box, which is unobtrusive and doesn't have any of the described CVT problems. Strange that Suzuki fit different boxes - you'd think it'd be more expensive - but then we don't have the 2-litre engine...