Yes, I did have these signs in my car at one time but have since thrown them away.
After years of seeing them posted on some homes that (in my opinion) weren't even sold at market value...they only create a false sense of value for the neighbours around it. The problem is...that many of you will call that agent since you ASSUME (and you know where I'm going...) they can do the same for you.
How do YOU as the consumer do anything about this? First of all, DO NOT just call the agent who sold a home 2 doors down and put the "sold over asking" sign on. Be vigilant and call at least 3 area professionals. I even go one step further and do a competitive analysis of the properties sold in your area so you REALLY know who it was that sold the home (in many cases, although you may see one agent's signs often...there may be dozens of buyers agents working hard behind the scenes to bring the buyer to the table...you should know this!!)
Buyers still decide on what is market value. The perception of what MAY be going on around you is not enough real information to make this decision.