I'm not sure what you mean by "a manufacturer appointed website". Does this mean you have no choice but to maintain a site they provide and where you have no control over it's look, feel, or content?
If you are planning on setting up a new domain and transferring your current domain name to that, what domain name would the existing site have? A 2nd newly obtained domain name? Or one available through the MFR?
Are you required by the MFR to use their provided site as your primary forward-facing promotional point of contact on the web?
These are all important points to help determine how you proceed.
If you make the new site nofollow, what would you use the new site for?
Having the need to maintain / promote two separate sites is always more challenging than focusing all your efforts on one site and really should be avoided at all costs if possible.
