After taking the test(s) for Civil 3D at AU; and a little research here:
http://autodesk.starttest.com/I offer this.
It is suprising how few people in the US are certified. The number shown for either the professional, or associate level is telling. Without violating the test agreement I can see why. There are a few instances where the most correct answer are not offered, and the best answer isn't the correct one. At least for test taking purposes.
Also there is at least two questions on the professional level that one could easily 'over think' the solution and
get the wrong value quite easily. (trust me, I did on the first pass through)
As the number of users is fairly small I could see where this 'certification' could at least get one an interview.
The rest would still be up to you. Of note, if I recall there is also an option to opt out of being shown in the searchable database. This sounds like an area where the certificate loses it's value should there be a large number of these ghost riders.