Towing mirrors

Does anyone know of any towing mirrors that actually work?

Ive tried various with my latest being:

Maypole with elastic straps, ok but can only see the centre portion of the van, with no idea where the wheel is or if the marker light might clip a high sided vehicle etc. 

Milenco aero but the clamps wont hold due to the angle of the edge on my Insignia mirrors.

Leisurewize rock steady, same problem as Milenco clamps.

Towsure couldnt see a thing

and a few that vibrated more than a pile driver!

I think perhaps the Maypole but convex so I can see more?

Any ideas appreciated especially from Insignia owners who have a fix for the likes of Milenco.

Thanks.