What if you were to lose your Kizashi?

[KuroNekko]

I thought the ISF ones were real? At least they've looked real on every ISF I've seen.

Yup, the tips are not connected to the exhaust. Exotics did it too but I think the ISF was the first "normal" car to do it before it became common.

I think the reception would've been better had Lexus opted for a more conservative style rather than the obnoxious vertical stack.

The exhaust design was rather different but I think it's what they were going for to differentiate this car. This thing is a Japanese M3 fighter with a V8 crammed in a compact sports sedan body. 416 HP, 0 to 60 in 4.6 seconds from a 5.0 liter normally-aspirated V8.

I think the double-stack exhaust outlets were a good design element to distinguish this beast from the lesser IS', much like how BMW uses hood bulges, side ports, and quad-exhausts on their M3s. However, if you want the exhaust tips to be part of the bumper design, they can't really be directly connected to the bumper.
Even Audi and Ferrari do this "fake exhaust" thing to have exhaust designs within the bumper.

[bootymac]

Yes, it's becoming more and more common whether we like it or not. It allows designers to better integrate the exhaust tips into the rear bumper but also feels like a cop out at the same time.