Hello RileyAnn,
And welcome to the forum.
I hope my answer does not confuse you any further, but there is a fly in the ointment..
You don't tell us the specific model of car that you have, as this could be a very significant factor in your choice of car. Bearing in mind you tell us that you have a post 1997 driving licence, that means you do not have entitlement BE or B+E, which limits your outfit to a combined Maximum authorised Mass not exceeding 3500Kg.
I have done a quick search for Smax vehicle weights, and I found this:
https://www.topgear.com/car-reviews/ford/s-max/20-tdci-180-titanium-5dr/spec
which lists this model as having a Gross Vehicle Mass (=MAM) of 2530kg. This is more than I was expecting, and if its the same as your model then I'm afraid your choice of caravan with its MTPLM (=MAM) of 1175kg when added to the cars MAM gives 2530 +1175 = 3705kg which exceeds your driving licence limit of 3500kg
I would be very surprised if any of the Smax range would come in with a GVW of 3500-1175=2325kg or less
Based on that assumption, I'm really sorry but you cannot legally drive your outfit.
In all other respects the towing ratio would be good at about 63% and generally the larger Fords earn high raise.
Sadly you choices are
Find a smaller tow vehicle with a GVW of less than 2325kg
Choose a smaller caravan with an MTPLM of less than 970kg
Or take the B+E extension test to remove the combined MAM limit of 3500kg
Sadly you cannot get round the figures by only part loading, as the regulation specifically looks at the MAM figures.