Can't help with the towing capacity, but do bear in mind that if the towed car weighs more than 750 Kg (as most do) it will need an operating system for the brakes.
Most vehicle makers are obliged to have a plate on the cab or under bonnet with the max permissable TRAIN weight or gross weight. First weigh your van loaded, then subtract that from the gross weight, and thats what you are allowed to tow. But remember this is gross train weight not max weight of just vehicle. Hope that helps.
Hello
In reply to your kind responses of help. I have downloaded the specification of our Swift and have to admit some of the jargon is beyond me. However, we have a local weighing station and perhaps once we've been there and weighed the Swift, hopefully a local dealer will be able to work it out for us.
Many thanks everyone who responded with help.
Thank you.