Hi Jennifer,
It's more than just your car insurance and whilst you might drive for years without being stopped it is what happens should you be involved in an accident that the real problems arise. I quote the experience of another forum contributer who owned a 2.5m wide Hobby:
"I can assure all of you that it is an expensive experience that you will regret, if you are involved in an accident, even when the following driver is at fault - I stopped safely to avoid a pedestrian, who was jaywalking, but the following driver didn't!
I had insured my van with the company that is quoted so often on here. I had given them full details of the HOBBY van in question - including overall length and width. I had been assured by the UK dealer that it was legal to tow a 2.5m width van in this country. I had notified my car insurer that I would be towing the caravan and that the towing vehicle had been modified from standard by the fitting of a towbar (How many of you have notified your insurer of that modification? It is a requirement). I "thought" I had done all of the right things and yet, when the accident happened, I was the one hammered from every direction - Police, Courts, 3rd Party Claims (because I was on the road in an illegal state), non payout by vehicle insurer, non-payout by caravan insurer and we even had to pay for our hospital treatment!
So, for any of you who have 'got everything covered', I wouldn't count on anything if you get involved in an accident."