2008 Ford Focus (Hatchback) mod.
 

http://s23.postimage.org/fb6ok3eif/DSC03593.jpg http://s8.postimage.org/6o9sg420h/DSC03590.jpg

I wanted to clean a bit the front side of this car. The fog lights are under 0.75 mm transparent plastic (it is used to build green houses). Seems ridgid enough to be kept in position by 2X 3.5 mm screws and to preserve the shape.

For the top grill, I wanted to block it outside I believe small "buckets" in the front do influence the flow and the aerodynamic drag. I tried mirrored plastic, but is too thin and not strong enough to keep the shape. I have to remove, it (it is fixed with double side adhesive tape TESSA) and reinforce it somehow... A CAD model will be great, Than I could make a 3D model of the grill block...
http://s17.postimg.org/612zg3cvf/DSC_0084_fb.jpg http://s23.postimg.org/5fiboe5tz/DSC_0085_fb.jpg

That is definitely a very clean look. Any plans for other modifications?

I would like to add an spoiler on the bottom rear window like this: http://www.tuningcarbonhoods.co.uk/m.../c/tcf6295.jpg
Rear wheels fairings will be interesting, but the aesthetic impact will be to big.
Maybe the deflectors in front of the wheels will be modified so the air will directed sidewards, so the air will hit the deflector in a 45 - 30 degrees.
30 mm lower body will be also nice, but I am happy with the current setting of the suspension and I would not like to change it...

The bonnet is too short so the wipers are not protected. The Opel Astra G was much better designed regarding this topic. I wonder if there is an bonnet extensions aftermarket.

Im digging the lower grill blocks and fog light covers, i especially like the bolts showing, it looks kind of tough. As for the the fog light covers even if they don't improve Aero flow, it will surely save some money when a rock decides to attack your fog lights!

I am not so sure the airflow is not improved with those covers over the fog lights. Previously there were some pockets where the air remains trapped with a increased of pressure. The appearance of the bolts is not so nice, but for now I can live with this. Maybe, in the future I will be able to redesign the bumper entirely using fiber glass. Thank you for the comment.

Good clean up of the airflow. Though not OEM finish, I think you have done a nice job fitting block off panels to a stock front end. I'll try to use your idea of the fog light cover idea on my Focus as well. Thanks!

What is the black material you used for the grille block?

The material si 1mm thick polypropylene with a satin (Matt) finish on one side bought from OBI (IT).
It will be nice to see an undertray for Focus hatchback.

UPDATE: Now the low grill block is made of aluminum 0.8mm plates.

bonnet
 

I completely enclosed the cowl area and windshield wipers of the T-100 at the Bonneville Salt Flats and it made no measurable improvement,even at 105 mph.

It doesn't look too bad. The wheel skirt is almost flat and can be placed without affecting the existing body. I wonder how beneficial.
http://s23.postimage.org/t5ww00o13/adszzx9_fairings.jpg

with this modification shown on the beginning of this post
http://s23.postimage.org/8945k5liv/DSC03588.jpg my medium consumption in the case a predominant (80%) usage on highway (130 km/h = 80.7 mph) modified (calculated based on the no. of km made between too full tanks) dropped from 6.8 l/100 km to 6.5 l/100 km ( US 34.6 mpg to 36.1 mpg). It's a 2.0 l diesel car, and I might be wrong. But even the noise level in the car changed. In good.

Looking for a kammback for my focus:
http://s10.postimg.org/i67yvw305/flow1.jpg

Stock vs. Kamm: http://s22.postimg.org/q6lm93fp9/flow_focus_1.jpg

Second version of Kamm: http://s4.postimg.org/v8rvvhv55/flow_focus_2.jpg

maybe less invasive modification, with positive results:
http://s7.postimg.org/kro5ql2sn/flow_focus_3.jpg

Aerodynamics are a harsh mistress. It looks smoother! Many vehicles seem to almost have one unbroken curve for the hood and windshield.

Do you want that for aesthetics? I think that you would have people snickering and saying "You know that does not do anything, right?"

At least, that is what I would expect someone to say that to me. I have yet to figure out what good that is supposed to do.

Since you posted those airflow pictures, you seem to be way ahead of me already, but just in case:

Have you used http://www.weirdcalculator.com/test/aero_template/? I use that so much that I bookmarked it. This is the one that I did most recently:

In my opinion, the Civic has a very good taper, but if you see how I extended the roof and trunk lines, the deck lid would need to be extended twenty-one inches for the air to reattach.

A Kammback would be great for your hatchback, but I do not think that anything else, save a [partial] boat-tail would be beneficial.

Yes, you are right. There are many "aesthetics" adds on cars that might make the things worst... I thought like this seeing elerons as extensions of SW...
But there are elerons that help even in that case:
https://www.youtube.com/watch?v=5UdROEOUyvg
This time, the apron on the bottom of rear glass, if long enough will make a difference (I think).
I think there are some other models where this apron will be less invasive and more effective than top roof kamm extension. I'm thinking on the work AndrzejM did and the shape of other models with a sport hatch (Citroen Xara, Opel astra G, Alfa romeo 146 and some other)

More, I hate the idea of template when taking about aerodynamics. There are so many alternatives, so why sticking with only one base profile..

While every snowflake may be unique, I wonder about raindrops.

You could start writing a haiku about this :)

My boat tail on focus based on 1939 Schlörwagen
http://s23.postimg.org/ajh9jkkmf/focus_boat_tail.jpg

39 celsius outside. Hot Italian weather. AC on.
Acceleration to 180 km/h with warm engine water temperature 102 Celsius.
Top gril block is gone.
Now same test 96 Celsius.

Schl'o'r
 

Remember,this car achieved only Cd 0.186 with its pseudo-Jaray tail.Exactly what Hucho warns about,and what Kamm and Koenig-Fachsenfeld kept in mind.

Only?

That's better than VW's LX-1 isn't it?

This Is Volkswagen's Crazy Awesome 261 MPG Car
As I recall reading a few headlines a week or two ago, some real life mpg numbers on the LX-1 were disappointing.

http://s184.photobucket.com/user/kac...?sort=3&page=1

Approved Method:
http://i184.photobucket.com/albums/x...ps01c6a614.jpg

Unapproved Method:
http://i184.photobucket.com/albums/x...psf675a830.jpg

better?
 

yes,it's a smidge better.The VW ARVW of 1981 was Cd 0.15.The 1st 1-liter car of 2006 was Cd 0.159,and the latest iteration is 0.189.
The Schl'o'r car was great in it's time and remarkable by today's standards.With the Fachsenfeld extensible tail,she'd approach Cd 0.12,and with wheel fairings like the 2013 Cambridge University Eco Racer (CUER) would be in Cd 0.10 territory.Stylists would hate it.

Now this is the Focus we should have gotten in 2008 instead of that USA-only turd they gave us.

I think this Honda has a similar back with my Focus, and the apron on the base of the rear windscreen is doing the job I thought it does: https://www.youtube.com/watch?v=5UdROEOUyvg