Weights and the law

Our driving licenses only allow us to tow a combined weight of 3500kg. The fully laden weight of our caravan is 1400kg BUT we never fill it to tow, we only carry basic kitchen equipment, water roll, waste tank and a couple of camping chairs (no clothing, bedding or food/drink etc).

So in theory we have 2100kg for the gross weight of the car. 

I get to change my car this year so have been looking at options, but the best options seem to be coming in slightly over at 2180kg.

My question is, if for any reason, someone decided to check our total weight, would they purely look at the figures (2180+1400 = illegal), or would they actually weigh us? There would only be 2 of us plus the dog in the car, with our luggage etc, so i'm sure we'd never actually be over the 3500kg.

Any advice gratefully received!