First of all I would like to say my knowledge of engines is pretty poor, I understand the basics and am fairly sure I have an issue here but would like to see what you guys think.
So, the situation is that my Radiator failed a few weeks ago. If I sat in a traffic jam on the motorway it would lose coolant, and I would have to top it up (it used around 1.5 liters over the course of a few weeks). If I looked through the front grills I could see at the drivers side of the radiator a small patch of coolant, so I took it to PSR automotive (who I rate very highly) and they said it needed replacing, No problem, I went for the higher end more expensive radiator and left the car with them for 2 days.
The radiator was replaced on Wednesday/Thursday, and I noticed on Friday that the coolant was about 1/2cm below the seam in the tank. No problem I thought, it has just been swapped over/needs settling in/other uneducated reason. I topped it up and thought nothing of it, but made sure to check it each time I used my car. Well today I took a look and here is the level at the moment:

As you can see it has dropped a little again.
The strange thing is that when I popped the bonnet to have a gander, I could hear a noise that I can only describe as if you had a wet balloon with a very small puncture, letting air out. it definately sounded like a small amount of air coming out through a damp hole, and it worried me slightly, so I had a look around and could see that the pipe in the picture below that goes into the heat shield looked wet as if it had been leaking, and has also rusted:

I will be giving PSR a call tomorrow, but wondered if this is a known issue with these cars? I am a little miffed to have spent so much getting the radiator replaced only to have the coolant drop again

If you got this far through my long post thank you, and if you reply thank you again

Q