It sounds like my exhaust is leaking from under the bonnet but can't see any leaks. I can also smell fumes. Anyone any Ideas what it could be

Sounds like the exhaust manifold gasket. Have a look around it for any signs of soot. A handy little trick it to hold a small piece of tissue paper near it, it'll flutter if there is gas escaping. If it's not the gasket, it's also possible that the manifold itself could have a crack in it.

Will have a closer look at it thanks mate

Could it be the flexi joint, quiet often these fail with no external signs of damage. Replaced both on my current Audi due to structural failure.

It had a new flexi welded in in December mate

How well was it welded in. Might have stumbled on possible poor job done on it.

Really well was an exhaust specialist took them hours to do it will double check though. Sounds like it's coming from drivers side

I had an exhaust leak sounding like it came from under the bonnet which turned out to be the gasket between the manifold and turbo. Cheap from a main dealer and not too bad to DiY. It can all be done from the top of the engine.

Same here currently. Manifold gasket is blowing and also cracked :(