Just a mention.. Why would a lock bar require engineering?
Secondly they dont have a hoist on the road, they will not note it is there... they care more for pods, strut braces and BOVs..
I dont think its true it would require a engineers ..
I have had a similar experence.. I doing 140 with bald tyres (bad alignment, weather and 2000km trip to qld caused this - to new tyres) when the ass end went out .. have not had an issue since I replaced the tyres and got a good alignment done perhaps this should be done first mine was way off!