I'm pretty bad about quantifying gains, and I don't have a MPG-sympathetic route to work any longer; it's all City. My mods are small, and taken singularly, probably insignificant. However, I'm taking a pretty conservative route (conservative inasmuch as my mods should produce results and not the opposite) and hoping that taken together, they'll produce a "death by 1000 cuts" affect.
>>Factory spoiler added (part of the drag reduction kit of the LE Eco trim level)
>>Purchased and installed LE Eco front underfloor (splash shield)
>>Small grill blocker L & R, middle radiator inlet.
>>Small grill blocker centerline, doubling size of factory one that was already there, middle radiator inlet.
>>Underfloor covers ahead of front tire spats to eliminate ugly-aero concavity
>>Added small underbody in-fill panel in area where underside tow hook used to reside.
In no particular order:
>>Air curtain! Love these, so I'm sketching one up to print that attaches at existing points just underneath the front of the car where the tire deflector is mounted and then is offset the front fender ahead of the front tires. Harder to do than it looks inasmuch as the CAD for the part is straight forward, the hard part is accurately documenting the attachment surfaces so that the thing fits! This part is causing me fits.
>>Proper radiator inlet ducting?
>>Flush wheel covers
>>Covers for faux fog-light area
>>Clean up front lower suspension control arm (fill hole, add round leading edge and trailing edge)?
>>Further modifications to rear spoiler, add an extension and sharpen the trailing edge (after being rear ended 11/2019 I'm at a reset with this one, and now I'm starting with the factory spoiler)
>>Add separation edge to area just above rear tail light; altogether Toyota generally seems to have done a pretty good job regarding this detail at the rear of the car, this would be the one area they didn't produce an edge and I suspect it was styling driven.
>>Enhance existing separation edges? Just like it sounds, sharpen them up! They all are radius'd to be sympathetic to molding and non-pedestrian hazards.