BTW - Turbo is shot - being replaced under extended engine warranty
(phew).

Now being told that the evaporator unit is acting up - what is this and
what does this mean? Can it be related to the Oil Sludge problem that
was supposed to be fixed last week?

What are these "chips" you mentioned. I am assuming this is an
"aftermarket" part - in this cased something to do withthe on-board
computer system that flashes the system and removes some of the
restrictions the stock system puts on the engine. How do I go about
looking into this and are there any good online resources?

Thanks