Hi mate, speak to the shop that fitted it asap. I do recall who fitted it btw.
Have you tried a fresh blower belt?
Send Agro a pm and seek his advice as well.
http://fordforums.com.au/member.php?u=1501
My belt squeaks a bit when it's cold, but runs quiet when it's warm. These head units will make a whining sound under load, but that's not what your describing I don't think.
In the mean time, try not to use the car until you've spoken with the shop / Agro.
tex