Glen,
Love your plan, have some food for thought.
Not sure how well funded you are, but, if you were like me, I was 99% energy and always under funded (read: loonnng hours). When you're under funded, there are many times you'll give away product to survive another day.
If you're funded well, I LOVE your game plan.
If not, then there is a world of learning ahead (read: flush cash down the toilet). If this is the case, think crawl, walk, run.
In either case, your advantage is product knowledge and passion. Go big creating the best pics and descriptions on the planet AND get your personality into those pics and text and videos. Folks like to do business with folks they like. GET YOUR FACE IN THERE! make it personal!!
Make that phone ring.
Look into craigslist and carve out your place there. If the car is right, consider eBay. Consider local newsprint classified websites and be sure to study Cars.com and AT to see if your pricing is low enough to be seen on a low to high price sort.
PPC can be a GREAT source of traffic, but, it's easy to ramp up spending and all your ROI can dissapear. It's important that you know your PPC reps game plan and have them slowly ramp up spending and keywords to find that "sweet spot" (max ROI).
Everyone here at DR will be looking forward to your adventure! Best wishes!!
Joe