progress...
Before I had a chance to go further with it, they got in contact with me this morning.
Long story short....
Car goes back to them on Tuesday morning (when I get back from work)
-They will rectify what ever the noise is, if, it as they suspect (same as what has been suggested here - i/c to throttle body) they are going to replace the hose/pipe.
-They will inspect every thing on the car, check, and sort out, if there is issues
-I will supposedly get a fully report on any additional work needed (we will see)
-They will do an oil flush and change, replace oil filter and gasket
-Manager will discuss with me when I get there as to 'compensation' for my troubles.
-As they want the car for most of the day to supposedly inspect thoroughly, they are offering to lend me a car for the day.

So we shall see how this actually pans out......