Just as a comment - I don’t know where the 750Kg. has come from, but it happens to be the maximum permitted weight of an unbraked trailer. There’s a further rider to that, from memory, that it must not be more than half the kerbweight of the towing vehicle which limit it to about 500Kg.
Good luck in finding a towbar. The only person I have spoken to who towed with an Mx-5 had made his own.
You can tow safely up to 85% of vehicle kerbweight, that is the caravan club recommended safe towing limit for a novice, someone experienced can tow to 100% of kerbweight.
I wouldn’t recommend making a towbar as they do need to be type approved as suitable for purpose.
The 85% is just the Caravan and Motorhome Club recommended upper limit for safety when towing caravans, and subject to all applicable laws and plated limits. It has nothing to do with the law whatsoever. Many cars have towing limits below 85% of their kerbweight or are train weight limited to well below 85% if the car is loaded to its MAM.
No vehicle can tow an unbraked trailer with a MAM of more than 750Kg regardless of its kerbweight, plated weight, or maximum train weight. Caravans of course generally have brakes. The thing about half the kerbweight for unbraked trailers dates back to 1982 I think - it may have been superseded, I don’t know. I had a link but is dead now and has been archived (see below)
It’s not necessary for a towbar on a pre-August-1998 car to be type-approved.
The caravan has brakes presumably, so should be legal if the towing limit is indeed 750Kg, but I am not sure how you would evidence that? Does the manual mention it, or is there a plate with a maximum train weight?
We have them on our MK1 NA and MK2 NB… but find them cheaper and better bars from Moss Miata in the States and import them in as the detachable ones appealed to me.
You will pay an import tax to line the customs pocket tho but even so it was not a killer… they are called hitch bars over there, the UK ones are not detachable and heavy things.
I think Speedy’s is detachable also?
I think I did I write up somewhere on the whole buying and fitting?
But no need to make your own they can be easily still be found, new or s/hand, I do have a spare but it is spoken for, sorry bud.
Been hitching up a trailer to ours when needed since starting with these little gems, dragging tools to shows ,rallies,meets and tech days.
If your stuck get in touch buddy, we know our stuff.