Mine has a wee bit of brinelling, but nothing like the OP's. It shoogles around in the mount, though (also Garmin) so I put a bit of black insulating tape across the bottom and round the mount to hold it in place. It still rattles a bit, but nothing drastic. My old eTrex 20 rattled too so I tried packing the mount with tape, but it hopped off and cost me half an hour's hoking through the grass verge to find it. It was orange; God knows if the 30x would be that easy to find.