I don't have the window rattle issue, nor the hatch cover one, but I have heard others have. Once in a while I hear some noise coming from the hatch area, but I ignore it as I have too much crap back there. My '07 I previously owned had a clunking noise from the rear. That really drove me crazy, but I found out that one was from the rear tie rod end bolt that came loose, and kept coming loose once in a while. My 2010 is good tho.
2010 MAZDA 3 S HB
MODS: RACING BEAT EXHAUST / RACING BEAT SPRINGS / LED 3RD BRAKE / 18x8 KONIG BACKBONE / 235/40ZR18 NEXEN N3000 / DDM ALUMINUM PEDALS / 35W 6000K HID / AIT MOD / CS SRI / 35% CERAMIC TINT