In my opinion the best way to convince your PSA'S is to tell them of your success with WAVE3. I personally drive around 100 miles per week and at least 2 times daily have people stop me to ask what the banner on my car is all about, I have actually made a sign that I carry in my car with all the information they need to log on so when I am driving all I have to do is hold up the sign!!
not to mention all the other great stuff you get from being a wave3 member!!
I hope this helps