What Car Was This?

[Sidney07]

So I'm driving north on I405 in Bellevue, Wa. and I see this new IS behind me. No plates on it yet. It's silver, and has maybe 19 or 20" wheels. Awesome looking car. As it passes me, I see on the back that instead of the IS 350 or 250 badge, it says SI 20. I do a double, then triple take. SI 20. What is it? Has anyone seen or heard of this model? In every way, it looks like the IS....except for this. Well, it could look different under the hood too!

[Ripcurl]

Could have had the trunk repainted and rebadged differently to signify something. I've seen some Lexus' come out of the shop with 300 RX quite a few times, or on the wrong side of the lid.