Alex,
I understand your concern for using your multi-million dollar brand in a PPC campaign but is this really much different than what Edmunds.com and other content/lead collection portals, review sites and business directories have been doing for years via SEO?
For example, type into Google "Checkered Flag Honda" and you will see on page one an SEO optimized page for your dealership from Edmunds.
On this page, you can post a review or get a price quote for a Honda or any car. Why would they optimize a page on their website for your dealership? Why would they take the time to create a page for most dealerships in the USA?
They are using your "brand" to generate traffic and leads. This has been going on for years and its a multi-million dollar business that drains equity from your brand.
YellowBot.com has an optimized page for your brand name:
So does Yelp.com:
So does SuperPages.com:
All of these people are using your multi-million dollar brand to generate Google Adsense revenue and to collect leads that they can sell for $15-$20 on the wholesale market.
These leads are then purchased and sold to 3 dealers for a total of $60. There are millions of dollars tied up in leveraging car dealership brand name.
The PPC campaign is nothing compared to the organically optimized pages that Edmunds has on most dealers in the USA.
The PPC caught your eye but the real money is that Edmunds.com is showing up on Google Page One for in the organic listings for searches on many dealer names.
As long as there are no "rules" about organically optimized content pages or profile pages, the only way to diminish the brand drain is to make sure lead collectors DO NOT show on Google Page One or two for searches on your brand name.
That's what I do for my clients who want to make that a reality.