Recently I seem to be seeing more and more cars with Isle of Man numberplates on .They can't all be on holiday here is there some sort of financial benefit to having your car registered there
Not sure of any benefits but I know that the IOM plates and Northern Irish plates are sold on at a premium to gullible types who think this somehow makes their cars look better.
Apart from Northern Ireland plates, all others can't be used in the UK for more than a year. This applies to Channel Island plates, and as the Isle of Man uses GBM for its ID, whereas Northern Ireland uses GB (though not part of it) I don't think they are allowed for permanent use either.