I have searched and searched but...

is there another fix apart from a new roof... ??

 

Depends how bad ur roof is mate, but a new roof is the best option, I know as I'm having 2 replace mine, not as big a job as u'd think but finding a good roof is the hard part!

 

replacing the metal is the result you want but welding bits into the roofskin will make it warp badly therefore people do the whole skin
the other option is grind out what you can treat it and filler it but you get a couple of years max out of that, the roof sufferers from (apart from not being treated well from factory)the water from the sunroof but also the consensation, just like the outside the inside condensates up too but its every mm of it so rusts very quickly

 

Cut the roof off anf put a carbon one on

 

The rust starts on the inside and eats its way through to the outside. If its just a few spots you can drill them out and fill the holes with weld then filler but you need to make sure its well sealed on the inside to stop it coming back.