Hello Peter
Given the information you have supplied, The only car the data I could find for 2001Vectra 2.0 Tdi (98 Bhp) list the vehicle as having a kerb weight of 1300 and max towed weight of 1300
Your caravan has an MTPLM of 1375 which gives you're a towing ratio of 1375/1300 = 105%
Even allowing for the fact that the caravan nose load (which I will assume 75Kg) is deducted from the MTPLm and allocated to the car, this mans the full laden caravan is 1300Kg and right at the top limits for the car.
This is very high and not to be recommended