Every other day I hear from a dealership who wants to use PPC to raise their Page Rank and each time I wonder where they are getting the idea that this is a valid use of their time. To this day I can only guess that they found a blog post or two (or three dozen) touting the need to raise page rank to get more traffic. While that is fine and dandy if your dream of growing up to be Andy Beal or Darren Rowse or even Jason Falls this isn't going to work for you.Why?
Well first off your PPC campaign will not raise your page rank. Page Rank is a vote, and each link to your site counts as a vote. Think of this as voting for your homecoming queen in high school. PPC campaigns by their very nature do not add links to your site, so they don't weigh in on the vote. Page Rank is a great way to measure a bloggers success, or how "trustworthy" a site is. However, it is link based and updated maybe 4 times a year so for your purposes it isn't very relevant.
The second reason this is a waste of your time is because you have a brick and mortar store with actual inventory. You have a reputation not only online but in your communities where it really counts. People are going to buy cars from you because you have a great website that is easy to navigate, a clean show room, helpful sales staff and great prices. The average person wouldn't know a page rank if it bit them in the ankle, and even if they did, the customer would absolutely rather buy their new car from the guy offering 3 free oil changes then the pr 6 website. Guaranteed.
As an aside if you know where people are getting the idea that dealerships should be worried about page rank please let me know in the comments! :) 
