Will still most likely get a pair of them and will post here how they go
As in improving the neck issue - not the ultimate performance review - unless that happens "by accident"
Will give them a good looking over
The steel tongue should be OK as it is simplicity itself
The buckle will hopefully be screwed together, or can be opened up and have a good look at the vital parts - again, they are not that complex either
Unfortunately the I don't have the equipment to measure the hardness of the steel bits and nor do I know what the specs are on the steel they are made from - would need to be better than mild steel.
Interesting. I find the seatbelt rubbing on my neck and was looking for a solution but in the meantime I make sure to slip it under my shirt collar. I'd like to try these extenders but the quality worries me too. It would solve my wife's problem about finding the seatbelt socket!