Results are in!
As I can't be bothered to calculate the cross sectional area of a Wee, the following are Cd*A results, where Fd (drag) = 0.5 * rho * Cd * A * v^2
rho = air density (1.2 kg/m^3 approx. standard atmosphere)
Cd = drag coefficient
A = cross sectional area, m^2
v = forward speed, m/s
The provided data gives me:
0.9 < Cd*A < 1.48
This includes rolling resistance as well as drag. The lower the number, the less drag the bike experiences, so the longer it'll roll/less fuel it'll use.
Thanks for your help