One thing is, on Allert Jacobs' blog, he mentions some crosswind trouble when he had only the front dolphin-esque fairing. He was able to eliminate the instability when he went all out, covering the whole bike.
"The front wheel fairing has to go to. I was quite confident that it would work and not affect the steering to much.
It turned out to be very scary to ride even with as little as 3 beaufort (about 10mph) side wind I did not dare to go over 35mph. It is a pity I made a mould and all without ever testing with a cardboard model."
Taken from:
http://www.velomobiel.nl/allert/Recu...0motorbike.htm