Pulling this thread back up from the dead to put these pictures in one place. I took them today at an abandoned gas station, of the Prius as it sits now. Just finished installing the converter cover this morning (mainly to prevent catalytic converter theft, but there should be some drag reduction from closing off more of the underside than the stock shield).
Based on the Audi A2 Tata/Warwick test of aerodynamic add-ons to a production car, I estimate it's sitting at ~0.20-0.21. I intend to calculate a more exact number in the coming weeks from a coast down test with wind velocity and temperature correction (I bought a Kestrel NV250 to provide that data).
Cue the picture dump.
Intake blanking
Blanking plate is now behind the grill, made of diamond aluminum sheet. Upper grill is open. Total grill area open to airflow is exactly 1/6 radiator area.
Wheel housing fairings (2018 Ford C-Max Hybrid)
Cribbed from Ford. Both are attached with plastic push pins; I added some plastic sheet in front to attach to as well (the Gorilla tape is just to seal up the exposed edge gaps).
Enlarged front wheel strakes
I've taken to calling these "strakes" as Honda marketing does. Made of indoor/outdoor rubber mat, these have held up for 2+ years now.
Hood opening gaskets
The hood opening is gasketed all the way around now--as in the current Prius Prime (but not regular Prius, oddly enough)--rather than just the front and back.
Front and rear air curtain ducts
Made of thin aluminum sheet. Convergent ducts emit sheets of faster-moving air over the wheel openings. I modeled the inlet/outlet sizes, placement, and direction/angle off the Hyundai Ioniq (front) and Honda Clarity (rear).
Exterior mirrors
Removed and holes plugged with fiberglass.
Extended catalytic converter cover
Courtesy of Miller in California. The other exhaust shop selling theft-prevention covers has a design that must be riveted in, so I went with this one that bolts in (using three different bolt heads) to rivnut inserts. Drilling through multiple steel sheets in the car's underbody was a b****, but otherwise it's an easy installation. Hopefully this makes the Prius a less-attractive target than the car sitting next to it, if it ever comes to that.
Smooth roof
The rear washer nozzle and antenna have been removed (along with the complete sound system).
Reduced ride height
Body has been lowered ~35mm with Tein H-tech springs, as detailed earlier in this thread (I think I installed these at 4,500 miles).
Rear air splitters (2012 Honda Insight)
Fairings from an Insight that sit behind the rear wheels and curve inward.
Rear window wiper
Removed entirely and plugged with a nylon cover.
I'm ready for my closeup, Mr. DeMille
