Aero mods will help at low speeds precisely because the drag is really bad to begin with. If you have some figures on your scooter (frontal area, Cd with rider), you can plug them in here and see what kinds of gains can be made by reducing Cd:
Resistance calculator: aerodynamic and rolling resistance - MetroMPG.com
Of course you've seen the Craig Vetter scooter aeromod thread?