Buddy the intercooler pipe is very easy to follow.. it's big and black and plastic.. Basically you can follow it from the EGR down and around to the front of the engine on the passenger side, through the intercooler, out the other side, and it will go back and up to the turbo. You can inspect with just a jack/ramps but I wouldn't go poking around as it's pretty awkward.
The lower IC pipes are really easy to check, just undo the undertray and you'll see two silicone pipes either side..
For example here is the one on the passenger side, mine infact when it popped off.
Drivers side one is similar and doesn't suffer quite as badly but still...
Boost hoses, with the rubber seals and new clips are around £60 a side.
Nearly every time it's the intercooler hoses that leak, I'm pushing over 30psi through my stock pipework so far and every single pipe is fine apart from the ones at the IC - That's where it will be leaking if it is.
otherwise it could be a faulty turbo..they are not that expensive all things considered especially if you look around..£300-£400 you can pick them up for, or have your existing one re-built if necessary.
If you have a boost leak you will notice a lack of performance.. I would probably avoid driving the car much/hard.. depending on what the problem is, if your turbo is damaged it might let go and ingest bits of metal into your engine (not good) or depending on if you have a boost leak, the car might see a lack of boost and try to compensate for it (making the turbo work harder than it actually has to).
