It is actually the sled whose metal is slowly being removed, the empeg probably was made of a higher quality steel I guess it could be because of the head unit that is mounted above my empeg sled which might be blocking the dimples from flexing upwards.

I've got a Subaru, so getting the sled in there involved some reasonably heavy handed fitting and dremeling of various parts. The empeg sled is about 5-8mm wider than both the head unit above it and the stuff below it. Initially I wanted to put the empeg in the top position, but that didn't work out at all, as the frame wouldn't even fit in the dashboard.