Aerodynamics of a bug

[graham]

I have been pretty active recently on this site as I have spent the past three or four days on the sofa with the sodding Flu. Anyway this is an idea I have had for a rear bumper/spoiler.It would work by releasing the pressure from the rear of the bug where the cars original design seems to act like a parachute.ie wings,apron,engine lid.The holes/vents in the wings etc would escape through vents and get channelled into the rear bumper at an angle to produce down force.In addition to this, the top of the bumper would be angled to produce more down force.It would be built to fit close to the body to eliminate what seems to also be the parachute shape of the standard bumper.Also the bottom center section could include veins.I have seen engine lids with holes behind the number plate this could be angled to produce more directional airflow.I am not sure of how it would effect the rear of the car but as I see it, it could possibly
1. create and add down force
2. release pressure from the rear wings,apron,engine lid.
3 create some rear end stability at high speed.

I have got an old porsche style body kit rear bumper that I was intending to use as a starting point .

All input welcome

Hope it turns out better than my sketches .