I recently read about having to declare a towbar as a modification to your insurance company too. So as I was renewing my car insurance, just a few weeks ago, I told my insurers about it. Of course I was expecting to have another lump sum added but to my astonishment - my insurance actually went down, yes down by about 35, I couldn't believe it but the call handler confirmed it again. I can only guess they thought no self respecting thief would want to steal an aging Honda CRV with a towbar!