You need to make up your own mind a bit

It has been discussed and discussed and discussed and discussed

Read here - we joined all the discussions and links in one thread under common questions -

http://forums.aussieveedubbers.com/viewtopic.php?tid=49875 

the search button is your freind


and what barry said

The stories will always be as conflicting as talking about which footy team people follow. You have to decide yourself.

What sort of car are you driving?

Here is what I make from all the fuss on this topic:
If you are the cautious or sympathetic type and you want to believe that you are giving your engine "the best" you will use premium and flashlube or a similar lead substiute...(If you just spent a shitload on rebuilding your engine then this is understandable)
If you like your ride and are just trying to do the right thing you'll use unleaded but also add a lead substitute "just in case"...
And if you know that your engine has the hardened valve seats that most VW's already have then you'll use unleaded alone and know that when ideally tuned that you can't get do any better or get any more power from your stock VW engine anyway!
Am I being fecicious? Sorry but this debate is so passe... :repuke
Cheers! T