One problem related to rear suspension springs has been reported for the 2005 Subaru Impreza. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Subaru Impreza based on all problems reported for the 2005 Impreza.
After ~3,000 miles on my 05 Impreza wrx sti a clunking noise appeared in the rear driver side suspension assembly. I do not know if this is potentially hazardous, but it definitely is an annoyance. The dealer diagnosed it as a misaligned spring and corrected the problem for 3 days, but then it reappeared. Many other owners I've spoken to have the same problem and it's supposedly a mfr defect with the strut assembly.