Be wary this is a rather long post, but anyone looking to save $700 on an ecomod you'll be glad you read it.
Under the 65+ efficiency mods, right height reduction is listed as being rather costly, gaining a rating of 3/4 $ signs. I'm assuming they mean lowering springs/coilovers.
During my ownership of a 1993 Mazda 626 (manual transmission, 2.0L DOHC 4 cyl), I reduced the ride height to help improve handling and aerodynamics, plus I wanted to close the especially ugly rear wheel well gap. I did this with spring clamps, a cheap way (just under 30 bucks) to lower almost any vehicle.
Note that spring clamps do not improve handling nearly as much as coil overs do for people looking for performance grade handling, however, they definitely serve the purpose of helping out with fuel efficiency. Spring clamps are a bit tedious to install, but they don't require any special mechanical knowledge, and can be removed at any time. They can also be adjusted so you can lower only the front wheels or just the back wheels.
You can drop your car anywhere from 1/2" to 2", depending on the length of the bolts that came with the clamps and your car's shocks. I would not recommend this for a car under warranty, but as far as I know the suspension returns to normal once they are removed, and it is much safer and smarter than lowering your car the wrong way (cutting coils).
It may seem they are "too cheap to be true", but I think that only applies to people seeking sport like performance in their suspension. However, even I saw a noticeable difference in the car's handling due to the lower center of gravity, it took corners at quicker speeds in a more agile and composed manner, allowing me to avoid the brakes without swerving dangerously or screeching the tires. I also noticed a slight gain in MPG by probably an average of 2 mpg (up from 33 to 35), a result of better aerodynamics as well as the more efficient cornering.
For those who don't know what spring clamps are, this is an example of them:
http://www.team-bhp.com/forum/iipcache/103871.jpg
I found them for 7 bucks for a set of two at my local NAPA. You need two for each wheel so the total cost was $28 plus tax, compare to lowering springs/coilovers which can cost upwards of $700!
If you have underpaneling, and would benefit from raising the car allowing air to bleed out underneath the smooth underside, these clamps can be flipped around to raise the vehicle as well, as seen here:
http://www.bodykitsonline.co.uk/spri...ower%20img.jpg