So a url like this: http://www.v6mustang.com/vb/members/benito334/index.php
isn't something that can just be redirected with easy rewrites.
It should be able to still be redirected the following way:
Rewrite rules to grab the username out of the url. The easy part.
Pass the url to a script, lets call it vbseomembers.php
vbseomembers.php takes the username, users a SQL query to query xf_user.php for the user_id associated with that username and then everything else is simply passing the user_id back to what would be the code in the traditional member.php redirect to get the new url.
Am I missing something? Is it that simple? Any issues that can be caused by doing it this way?