As regards the Supagard, when I negotiated my IS300h Luxury last year I was told I would have a free monthly valet whilst I had the car (inside & out), so for me it was well worth it. I've had the car since 31st July, it's kept clean and I haven't washed it once!
As regards my experience of the car, well I love it. The fuel economy may not be quite as good as I'd hoped, but it's still reasonable, and certainly a lot better than my old IS250. I know it will also improve when the weather warms up. Is it worth the money, well I'm not sure, but I'm still pleased I bought it and would likely do so again. The dealer is also fantastic with after sales attention being as good as the pre sales which is not always the case elsewhere. I guess that's what you pay for.