Well after 2 hours of crawling under the car and removing wheels & body parts I decided to look under the bonnet (hood) and removed the two covers, one over the passenger air filter and the other over the brake fluid reservoir/servo - and there they were
Two 10mm silver coloured rubber/plastic tubes sticking out sideways about 10cm into the under bonnet drain boxes for the front screen/wiper area drainage. Both easily accessible once the top plastic covers were unclipped and after a few quick squeezes they discharged a cupful of sludge then ran clear - even gurgling as the water drained from the moon roof gulleys.
A simple two minute job to check once or twice a year.
Sooo happy now!
