hi phil
not one of the other posts mentioned to tell them you have insurance .ask around your mates or work colleagues this is what i done keep writing the letters put a stamped address envelope with a copy of your insurance in it , also try business parks, rugby clubs, football clubs ,hotels ,golf course. all these i have i didn't get a quick response
more declines than offers till they realise they have a problem keep at it buddy .check out grimreaper he has some letters you might want to use they worked for me
regards
davy