A quick google for the towing weight of a Rover 620ti shows it at 1200kg max.
An MG Metro at approx 1000kg plus 4-wheel trailer at about 500kg gives 1500kg total. So I'd have a rough guess, you were at least a quarter tonne over weight on that one, maybe even 300kg ?
Secondly, the ZT (without knowing what engine & gearbox were fitted) at best must've been around 1400kg if a 1.8 manual, so once again you'd have been way over your weight limit of a braked trailer behind the 620ti, let alone that of an A-frame which I'd be quite certain had no coupling to the brakes of the ZT ?
If it did, maybe you could tell us all how the coupled/connected system actually worked ??
Just because you proudly claim your car with 200bhp made it feel like 'it wasn't there once rolling' does not:
a) make either set-up legal or safe.
b) mean you'd be insured if you lose control on a bend or whilst braking unexpectedly and have a head-on with an innocent oncoming car or motorcyclist.
Equally, your consistant disregard (I'm sure I've read elsewhere of you towing an MG Montego back from Cornwall with the 620ti - again completely illegal based on 1200kg towing weight) to ensure your combination is safe will mean that you are:
c) over-loading both the 620 braking and suspension systems, not to mention the rear floor, integral chassis rails and tow bar, which will have all been tested and found to be safe UP TO THE MANUFACTURERS SPECIFIED LIMIT, which as previously said appears to be 1200kg.
So please stop posting images of illegal towing set-ups, which may give the less well informed members the wrong idea of what they can and cannot do on the public highway. Remember, it could be another forum member that you hit
I dread to think how you'd sleep at night if you end up ploughing through a crowded school bus stop one day....
Please think before you post on here, or attach anything to your 620ti towbar