Subaru has always had a factory boost gauge as an option and one is available for the '08 WRX and '08 STI:
http://www.japanparts.com/images/Ima...ase=1&no=12118
The gauge looks a lot nicer this year and Subaru probably contracted out to Defi; the similarities are striking (and it's rumoured Defi created the gauge cluster for the 04-07...maybe even '08.)
I don't know if this is available as a dealership option like the older (much uglier) boost gauge. For that price though, I'd probably just buy the Defi boost gauge.
