Supragard is a massive con. My wife succumbed to the hard sell on her IS, with the dealer (Chester) taking 10 mins plus to say how poor quality Lexus paintwork was and why it was necessary. I found his manner on the verge of aggressive and once he realised I was not the decision maker, he shut me out of the conversation. I then observed carefully and noted all the tactics to be used as ammo when I bought my IS-F. I was planning to wait for him to rubbish the paint, dig himself a nice hole, then demand it for free on the grounds that the factory paint was not fit for purpose. I was also going to dib him in to the Dealership Owner for being so derogatory about Lexus to customers. In the end it was anything but Super and provided no Garding of any description (or spelling). I also bought my IS-F from Wolverhampton.
The punter who bought my RC-F new from Chester also had it put on, presumably as a result of such sales tactics . I bought the car 3 months later and when I had a query about some hard to shift watermarks, was told in a very abrupt manner by Chester that it was nothing to do with them and I should speak to Supragard. Of course, there is some small print that says that the guarantee is not transferable between owners, and I was basically told to FRO by Supragard too.
I notice you are in Cheshire Nean; would you be by any chance buying it from Chester? If so, the service guys there are great, so don't be put off by some dodgy sales people