On most of our customer VW's we supply and use Synta Silver & Gold, on the older cars you have an option for using both and also very dependant on the customers choice.
Some of our customer prefer fully synthetic.
Our demo car runs Royal Purple 20/50w full race synthetic oil for the summer and then 15/40w for the colder months, both oils have reduced the oil drive temperature by up to 10c in some cases, although the thicker oil will run hotter then the lighter oil.
We provide engine flushes on most older cars now, and to date we have had no problems, we also recommend to all our customer that the oil is changes every 5k miles, a better policy or insurance then the VW service interval recommendations.
Also to reply to the 1.6 Driver question, Synta Silver with a genuine filter should be fine for the EZ coded engine, hope this helps.