Re: weird noise when switching off key
the hissing is your power steering, prolly a seal or summant.
the bushes are easily and cheaply replaced, but get a mechanic to do it or you could lose teeth without the right tools.
most likely need to regas your AC, there are kits on e bay that do a good job for next to nothing.
i dunno what the noise is without hearing it, but my 147 makes some kinda noise when i turn it off aswell, like an electric motor moving something in the engine or ventilation system, but no idea what it is