Here's an image progression for an inflated boat tail on a 1st-gen CRX.
The 3 articulated nested-pans serve to add some rigidity at the base,and dampen aeroelastic effects that would otherwise wag the tail.
Piggy-backing onto a cruise control circuit would allow for automatic operation.
Some micro-switches and a locking solenoid would be involved.A 2-way reversing damper would allow for inflation and evacuation of the envelope,with a 12-VDC blower doing the heavy work.Once the envelope is pressurized,the fan is acting against a dead head,and current demands fall off.
When pan#2 is perpendicular to the road,it' drag helps with the deployment.
