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Anybody around with some aerodynamics understanding to help me out?

I took some photos of my 2002 (Gen'2) Honda CR-V. I think there's room for improvments by covering it... Maybe get some noticeable MPG out of that.
For info, this SUV is meant for long highway drives, followed by light off-roading (not necessarilly well maintained forest dirtroads or paved with potholes, or the likes). I did not meant to buy it for city driving, nor for heavy off roading though I can't exclude to ever have to do with it a little approach drive through rocks or cross rivers...

BTW, if I do tuft testing, what speed is needed? I'd have to attach a camera somehow at different spots.

Pic 1:
On the right, we can see the gas tank sticking out protected by a tubing, and in front 2 parallel frame beams.
The muffler and drive shaft (also protected by a V-shaped bent metal rod) probably get very hot so can't be covered much.
The rear wheels are not covered, partly because of clearance I suspect. Note that the clearance is excelent: There's lots of room in the middle so this SUV could pass pretty big rocks with proper driving, to pass them by rolling on top of the high points.

http://rock-climbing.kicks-ass.net/BUMPER/_7075603.JPG

Pic 2:
There we can see the bottom of the bumper and the cladding under the engine. I assume that part protects from dust but also evens the flow of air going into the engine for proper cooling.
Notes:
- The cladding is not uniform, and could be smoothed out.
- There's no lip to create a depression or push air to the side.
- There's no lip in front of the tires to reduce wheel drag and car stability (though it's pretty stable passing trucks).
http://rock-climbing.kicks-ass.net/BUMPER/_7075605.JPG

Pic 3:
A close-up of the gas tank and rear. Note: If I create a sloping underbody cover here, I feel like adding room for a portable gas jug in front.
Adding a cover has the added benefit of protecting the brake lines from debris.
http://rock-climbing.kicks-ass.net/BUMPER/_7075607.JPG

Pic 4/5:
The rear passenger side... Not much to do except maybe cover from the rear suspension to the back. I'd have to see what parts are moving with the suspension. The shiny part seems to be a heat shield for the spare wheel well.

http://rock-climbing.kicks-ass.net/BUMPER/_7075609.JPG
http://rock-climbing.kicks-ass.net/BUMPER/_7075610.JPG

Pic 6:
Front wheel well passenger side.
The wheel is totally exposed to wind as well as the hole where the wishbone moves. The space is open with the engine bay and wheel well. A big fat lip might help there, or a vortex to create a bypass bubble around the hole without creating too much turbulence.

http://rock-climbing.kicks-ass.net/BUMPER/_7075618.JPG

Pic 7/8:
Rear driver side (and passenger side) wheel shooting from the back of the truck.

Definitively some flattening would help the flow there. The trick is doing that with the large moving suspension frame. I don't have any ideas except maybe using some kind of flexible rugged fabric. Again I don't know what are the cooling characteristics that need to be preserved.

http://rock-climbing.kicks-ass.net/BUMPER/_7075624.JPG
http://rock-climbing.kicks-ass.net/BUMPER/_7075626.JPG

Pic 9/10/11:
Some details of the body aerodynamics

The wipers are not well protected it seems.
The rearview mirror is kinda flat, and the pilar holding it kinda big, must create drag.

http://rock-climbing.kicks-ass.net/BUMPER/_7075627.JPG
http://rock-climbing.kicks-ass.net/BUMPER/_7075628.JPG
http://rock-climbing.kicks-ass.net/BUMPER/_7075629.JPG

You might want to try an air dam. Gassavers.org has a lot of discussion of aerodynamic mods at http://www.gassavers.org/forumdisplay.php?f=11. I enjoyed Kitcar's DIY video for his Dodge truck that links from there.

Goto automobiles.honda.com. Take a look at the underbody aero trim of the 07 CRV. That might give you some good ideas. (Notice for example the half-strakes in front of the front wheels.)

-mr. bill

Thanks Bill, great idea. Gotta go to the 3D view...

Here's what I gathered:

http://rock-climbing.kicks-ass.net/BUMPER/CRV07-LS.JPG
1- bumper angle changed to get more air going up.
2- Rear roof angle seems mostly unchanged: maybe no need for a spoiler
or vortex generators there.
3- Wheels get their air dam now. Also not visible, I think there's a partial lip
over the engine bay, which is not continuous.
4- There is some aerodynamic underbody cladding now to help the air flow around things. Also the gas tang is not as easy to identify, it doesn't ride as low I think.
5- There's an air dam for the rear wheels, but just a vertical piece. Why not angled?!

http://rock-climbing.kicks-ass.net/BUMPER/CRV07-RS.JPG
Another view of the same stuff.
1- Note that the underbody starts abruptly in front. Maybe it's in the air bubble so they don't need a slope. The exposed slopes are very gentle.

http://rock-climbing.kicks-ass.net/BUMPER/CRV07-FRONT.JPG

Notice the lips for the air.
As all cars, the wheel damcovers 2/3 of the wheel.
The engine dam is separate so it allows flow between the wheel and its start.
It has an abroupt interruption, and exposes the differential to straight-thru air. Why? Cooling or just already aerodynamic so reduces the total surface?

http://rock-climbing.kicks-ass.net/BUMPER/CRV07-REAR.JPG
Nothing major on the rear.

http://rock-climbing.kicks-ass.net/BUMPER/CRV07-BOTTOM.JPG

I tried to draw where and how I think the air flows... I marked the wheel air dams. Note that the engine has no cover at all as the Gen'2 has a partial cover going around it. I think they make a bubble around it for air flow, which gets filled with the turbulent air comming through the engine.
There are still some gams between the rear bumper and the body