the diffuser is from civic si mugen.. i think it would be awesome it they made diffuser for fit.. i kinda like the 09 rear bumper..

 

ahh it's not the best of photoshops, but it gets the point across
i think that would be pretty rad!

 

I try not to be a "hater" but that looks like it came off a GM SUV and not on their best day.

 

From what I have been able to figure out by looking at pictures of various diffusers, the Noblesse unit is the only one that comes anywhere near being a 'real' diffuser. It appears to be made of two parts; a box-like unit that smooths the center of the car from behind the rear axle back to the bumper, then a second trim piece that fills the gap between the boxy piece and the bumper and mates up to the bumper. Only the the trim piece has diffusing fins so I'm not sure how effective it would really be.

Oops never mind. I forgot I was on fitfreak, where looks aren't the main thing, they're the only thing.

 

I think the Fit would look nice with a subtle rear diffuser.

 

Not bad beside the sides not meeting up.

 

I'll goiv you an A for effort!(does that even make sense??) I agree with Tool, a subtle diffuser would be a welcomed addition.