my guess is that they were getting buffed early on when they were running less often and to less locations.....now that they are traveling distance and are out running for longer periods of time they will probably ride longer....also i have seen 06 pieces still running so it must just depend on the car.
its funny all this hooplah over reefers now has made me pretty much put them on the back burner.....popularity ruins and cheapens everything.....back to csx waffles and ns mini ridge.....no one ever really rocked plain cars proper anyway....