some insurers make a big fuss about having a roll cage....mainly because they thinking:
1. wondering why you want a roll cage
2. you are obviously a rally/motorsport fan and will therefore try and pretend you too are a rally driver, and like all rally drivers, will end up in a hedge before too long!
3. roll cages look cool - and this will no doubt excite other younger drivers to try and race you...and you, being an owner of a roll cage will oblige...
Sounds totally stuipid and unfair I know - but they look into pretty much every combination of a drivers intent and match that to past history of number of claims of drivers who run a cage...etc