I listed with CarGurus as a private seller not once, but twice on the same car. First time I listed the car at my own price, and they gave me a good price rating two days later after my payment had cleared to them. It was dropped to a fair price. So I canceled the ad until I could afford to lower the price a month later I relisted the vehicle at their suggested price which they gave me a good price rating again, but when my payment cleared, the rating was dropped to a fair deal rating again. When I called, they said it had nothing to do with anything but the fair market value. It's awful funny how the fair market value could change after two days not once but twice! Sellers Beware this site is a scam!
We certainly understand the frustration. The private seller market fluctuates daily and I'm afraid we are unable to predict these changes. This can cause deal ratings to change for vehicles that are right on the cusp of the market value.
In our What is IMV? Article it is noted that we update our IMV calculations daily. Additionally, CarGurus gives you as much time as you need to keep your vehicle listed before it sells. We recommend keeping it at the current price and seeing which shoppers are interested!