Nothing at all.
Leaves and debris get caught behind the front mudguards which trap moisture. This might cause rust in older models.
I haves had no hassles with mine. It is a really fun car to drive and puts a lot of cars to shame when you punt it through the tight stuff.
You need to drive the car hard to get the best out of the engine as it responds well to being held in the high rev range. The down side of the engine is that it doesn't develop a great deal of torque, so off the line performance is a bit sluggish. Keep the thing above 4000 RPM and it will really boogie (mine has a full exhaust system on it, but no work on the intakes or the chip).
The car itself is very well appointed. The only thing I have added is an upgraded sound system with a ten disc stacker. The standard sound system was rubbish.
I Love my Eunos, definitely drives and handles well. Very Sleek and sexy and it has not dated at all. Go the Luxury Model because there are more features. Sun roof really makes this car and It gets a lot of looks.
The car is very hard to start off the line so I would not recommend this car to people that would want to drag from the traffic lights. I would recommend a 300zx for people that want to start quickly I own a 300zx now and it absolutely fly's.