To expect people to fix bikes on racks on cars safely?

[Blu]

And that aybe people using them should be required to be taught how to do it by a qualified supplier?

Because driving on the motorway yesterday I had to take evasive action TWICE (once on the M6, once on the M40) because of bikes that had fallen off the back of cars.
No sign of either of them having crashed through the windscreens of the cars following but for all I know either could have caused crashes amongst cars travelling behind me. The one on the M6 was in the overtaking lane.

Bloody dangerous.

I was driving on a dual carriageway when I heard a terrific crunch.

Someone's bikes had fallen off the back of their car - on the opposite side of the road - and were run over by a lorry but could have caused a really nasty accident. Don't know if there's a law about this, but there certainly should be.

Very scary.

there is a law, it is called the highway code see under point 98.

and yanbu at all.
so scary, glad to hear that you didn't have an accident caused by this.