ToomanyVolvos;136531 wroteSurely wheel bearings wouldn't be a likely reason with just 49 K. I always thought modern sealed bearings should last at least 300-400K.
Afterall Volvo started as a bearing company, I'd expect their design and spec to be class leading.
Your car's only just run-in, hope it's something real simple. Out of interest are you running roof racks? My V50 had an odd noise at about the same speed until I took off the silly aftermarket racks.
The issue was not the bearings but insufficient retention to the hub (press fitting) causing the bearings to get out of place and then fail
Hence the bearing retainer plates