Using the supplied AutoGlym Super Resin Polish will, over time remove the Supaguard. That is why they included the AutoGlym Extra Gloss Protection which is pretty much the same as the Supaguard they applied in the first place.
There is nothing wrong with Supaguard other than the big wedge of cash you stumped up for it and the claims that it lasts xx years. Most people think that they never have to polish / wax their car again which is one reason why it gets a rough ride.
The other reason it gets slated is that there are better paint sealants around, as Daffy mentions, but that doesn't mean to say that you have to remove the Supaguard... It will do the job, just won't be as durable as some other products on the market. I would keep with AutoGlym until you have used up the Extra Gloss Protection.
How long since the car was treated? You can put wax straight on top of the Supaguard - you don't necessarily need to take it off but I would clay your car if it is more than a month since the Supaguard was applied - but then use SRP + EGP again... Before you wax it.
So in short:
1) Supaguard is expensive and not as good as some of the other products around, however since you have invested (heavily) in this product, you might as well use it until it runs out - then seek a better alternative...
2) Clay your car if it is more than a month since the Supaguard was applied, then use the Super Resin Polish, then the Extra Gloss Protection then put a good (hard) wax on - and I'm not talking Turtlewax from Halfrauds! The Dodo Juice range are good. Zymol are also very good. P21S is excellent but lasts about a week...
I applied Super Resin Polish with a machine polisher, then Extra Gloss Protection followed by Dodo Juice Blue Velvet about 3 months ago and water is still beading... I used the AutoGlym products as I had them already - next time I will be using a better product. Like Jet Seal 109.
See here for pics of my car and a detail of a Candy White...
http://www.seatcupra.net/forums/showthread.php?t=147805
Of course if money is no object then bin the AutoGlym stuff and do what Daffy says!
hth,
fM