Just bought the above this weekend.

When we parked up at home after a short drive out, there was a fairly loud hissing noise coming from the front right of the engine bay. A quick lift of the bonnet/inspection underneath showed no obvious leak (thought it might be the radiator at first) so based on previous similar questions on here I would have to assume it is either relatted to the turbo or the aircon system.

Unlike previous poster, the hissing went on for a good 10 mins after parking up before slowly dieing away (as the pressure obviously eased up)

Took it out for a few drives afterwards (with aircon on and without) to see if it re-occurred but nothing.

We did get a warrenty so I will take it back to the vendor this week but it would be useful to add a bit of knowledge to my claim for inspection/repair!!