I personally love that we have 2 OEM + manufacturers to choose from. On my personal BRZ I have the TRD Steering Wheel and the Toyota frameless mirror, and recently I have been lusting after the TRD shift knob. However I am a huge fan of the STi lips, and the STi wheels. I don't think it makes the car look weird at all, in fact the people who are "in the know" will know exactly why you have TRD parts on your Subaru or STi parts on your Toyota/Scion. I've always liked the subtle parts that normal people can't spot, but a true car person will notice it instantly, and I think both TRD and STi make some really nice parts that fit in that mentality perfectly.
So basically, a Big +1 for mix and matching STi and TRD!!!
Thanks,
Rick