In reply to gimmergimmer:
> 4. What happened to the simple life.
Your lack of use of paragraphs is contributing to the lack of life simplicity
> but locking arm won't come down
Why not, is it hitting the bumper or something?
> Have Honda fitted the wrong sort of tow bar
They all have 50mm balls so it doesn't matter what tow bar you fit. It's a standard size. Yes some sit further away from the car as others, but as long as you have about 3" clearance which it looks like you do, I can't see why they wouldn't work.
The two racks you are looking at are both clamp on types so shouldn't be fussy.
If it was a bolt on, then you would need a flange type tow bar.
It sounds like you either have a defective tow ball size (really unlikely), or the racks you tried to fit are faulty (also rather unlikely) or it's just a technique issue when fitting.
> 2. Is Halford suggestion any good and likely to work
It's the one I would go for as it's so much cheaper. Yes a few more steps to fitting it. Guess it depends on how often you plan on using it.