Very interesting, but I notice that this thread has been going for over 6 months and only 141 have reported spring breakage. Although, 87 have been 02s and 44 have been 03s. Unfortunately, only 56 gave build date or VIN info.
Going through the threads show that only two of the 141 had under 20,000 miles. Engine damage was reported by 20 of the 141, but most that reported damage did not give mileage.
There were almost 17,000 Z06s built in 02 & 03. Can data from 56 really conclude anything? It does look like 02s may have something going on though.
Maybe I'll change mine in the spring for piece of mind.