The overall assembly quality of the Imprezas ('02 WRX, '04 STi and '04 Forester) we have owned is better than our '04 Acura TL (USA assembeled) but slightly below our '02 Acura RSX (Japan assembeled).
The issue isn't specific to Subaru, non of the cars we have owned recently have had great paint. The paint on the '04 STi seemed be better formulated compared to the '02 WRX.