Another week on and no change. They apparently have called Audi technicians in from somewhere else but they cannot cure poor starting from cold.
On Vectras there was a long running thread on a software fault on an ecu which effectively gave the parameters for cold start - there was a field remedy whch read as follows:
"Field Remedy: 1579
Subject:Engine - Bad cold start behaviour Models:Engines:Option:Vectra-C 2002...2003Y20DTHNoneComplaint:Bad cold start behaviour especially between +5 and +9°C coolant temperature.Cause:Problem caused by Software deviation.Production:Production implementation pending, details will be communicated upon availability.
Remedy:
In case of customer complaint reprogram with new software (decrease of cold start injection amount and modified preheat phase timing).Available with TIS-CD 40, April 2003.Functional Group:J - Engine Complaint Group:13 - No/Poor Function Trouble Code:None "
God knows what Audi are doing - they have told him to keep driving the loan car (A4 V6)
with the service light on. He has now done 6000 miles in the loaner.