Hello James,
As is so often the case when people ask for tow car advice we are unable to be specific. If you look through the list of Audi cars (and this applies to most manufacturers) you will see that they often reuse the the name of a model, they populate it with different engines and transmissions, body styles and trim levels, and then some years they update a model with a different engine output or other details which can affect its towing capabilities.
If you dig deeper into the specifications you find that what appears to be virtually identical cars, can have very different technical specifications. The Volkswagen Audi Group inc Seat and Skoda, are notorious for using the same engine but with several different power outputs so simply quoting 2.0L is not enough.
To pin down the exact car (s) you are looking at we need We need:-
Make
Model
Year
Engine CC
Power output
Transmission
Body style(e.g. saloon, estate coupe or manufactures designation)
Trim Level(e.g. S, SE, GT etc)
I have yet to find a database of vehicle specifications that is complete and accurate, This includes those used by caravan dealers. So what ever site or data base you use, you cannot guarantee their results to be accurate.
If you can gather the information from reliable sources its actually quite easy to compare basic information such as towing ratio's. Reliable sources include data plates on the vehicle, the V5c Registration document, the owners hand book for the vehicle.
It is always a good idea to keep the towing ratio within the capability of the car and as small as possible. The UK caravan industry recommends not exceeding 85%. This is only guidance and not law, and sticking to it offers no guarantees of safety or a good match. Good towing is down to a lot of factors including proper maintenance, safe loading and nose weight trimming but probably most of all good driving.
Now you tell us you are new to towing a caravan, and based on the figures I have seen for some of the vehicles you have suggested I do have another concern. The cars you have suggested could have a Gross Vehicle Weight (Car fully loaded)of 2000Kg or more. If you are looking at a caravan with an MTPL of 1500, then the combined gross Train Weight or Combined Maximum Authorised Mass (MAM) is going to be in the region of 3500kg. If the combined MAM exceeds 3500kg you must have either Cat BE or B+E on your driving licence.
If you passed your driving test after 1 Jan 1997 you will not have BE or B+E unless you have taken the E extension towing test.