Consumer Reports will also, for only like $20, give you a report on what the dealers in the area are paying for the car and give you a guesstimate on how much profit they like to make. SUVs can be discounted a lot more. When we bought our Fit we started the negotiation at their cost plus $300 and they talked us up to their cost plus $500.
You can look up "Invoice" online easily. I dont know if that's what you mean by dealers paying because you are a really smart guy and I assume you understand that there is that price + Volume incentives + Holdbacks which is where the 2nd half of the profit comes from. I dont know what consumer reports publishes but I didnt think they made an estimate on total per vehicle profit (maybe they do). Right now the SUV/Truck market is Hot therefore discounting isnt as good as it used to be say in 2010. Depends on the Brand too. Mazda is giving out pretty good deals, Toyota and Honda not so much.