@Dave-ROR
My guess is that the R version will be branded as "RS" (release series; that's what scion does will all their "special models"). They are one example of putting in something that is worth lets say $1000 into the car and charging you an extra $2000.
I've went to the dealer for parts and installations. The parts are available online and are cheaper and usually places like trdpsparks etc. not only sell them for less, but have group buys that bring the price down even further. But that's not really where you save the most. When it comes to installation at a Scion dealer ...
... I laugh every time they give me an estimate. If the part is $300, they will charge you close to a $1000 with the installation (compare to lets say a shop that will do it for $600). Those are not exact numbers, but the proportions are about right based on my experience. And finally, especially if its something simple, I rather just do it myself. That way its not only cheaper, but I get the enjoyment out of doing it myself.
Again, this is not me saying "don't buy the R version, its crap". I don't know that and I highly doubt that will be the case. I was just pointing out that it's not for everyone and that there are better alternatives (as far as best bang for the buck and possibly getting some enjoyment/pride out of DIY)