1st gen Honda Insight boattail idea
 

I have owned my 75k+ 2000 Insight for a little over two months now. I like lean burn, and the cd is great, but I would like to lean cruise at a higher speed than I can right now. I have done a grille block with good results (66.7 mpg on the oem gauge). I figure the greatest improvement I can make now is by making the rear end more aerodynamic. Ultimately I would like to install a trailer hitch mount and build a boattail/extra storage attachment for it, perhaps for long trips. While considering this, I thought of a less effective, but more usable idea to improve rear end aero. I may try to design flaps out of clear plastic that rest against the rear at low speeds. As speed increases, they would pivot out to follow the body contours. If it was really well engineered (probably beyond my ability), the airflow could pull them out and they would return when airflow dropped. For me I would probably motorize it. I figure I have about a 32" by 27" area at the back to work with. To those who know a little more about such things than me: good idea or likely not worth the effort?

We certainly don't want to discourage any new boat tail projects, but getting a decent design, with reliable attachment and good durability is a real engineering challenge. I would recommend that you start by thoroughly reading this thread:

http://ecomodder.com/forum/showthrea...ect-13533.html

It a good account of the efforts of one Ecomodder member in building a decent quality boat tail.

I think your ideas of using folding sections is very complex given the rather complex shape of the rear of the car. Read the thread and think some more about it.

flaps
 

The flaps would have to be sculpted very carefully and integrate perfectly to the cars tail when deployed to provide the 'clean' flow needed for a tail to work.This might aggravate their ability to 'nest' together when not deployed.
The airflow might want to just pound them rater than deploy them.Also,when not deployed,they could pose a safety issue to passing pedestrians if they were to walk into the covered mechanicals.
Additionally,when 'nested' the panels might interfere with lights and license plate.