All those car referral companies are out to make money. True car and the car buying programs (NRA has the same one many others use)... They actually will connect you with volume dealers that will give you decent prices. In my market, they come in a thousand or more under what the local dealers are willing to do. I just window shop on new vehicles more often than not.
If you do any of them, feel free to give out your mailing address, but use a trash Email address and setup a google voice number for the phone calls....you'll get called at least 10-20 times per dealership on the list and get tagged by their auto-spammers.
I purchased a new car a few years back
**For those that told you they had the vehicle on the lot and didn't...I know how to fix that. I talked to 2 dealerships that told me they had the inventory I wanted...when I tried to confirm, they kept telling me they lost the inventory (was on other lots in their network). Finally, I called a third dealership and they had similar issues, but upgraded the order to get me the closest thing they could, but didn't charge me for the extra features.

I was dealing with dealerships 100-200 miles away. I had them confirm EXACTLY what they had and fax me a copy of the invoice with their sales price, including tax. I then put a binder on it using my AMEX and drove there with a check for the exact amount of the sale. If you do this, you're working all over the phone and don't have to worry about their squirrelly crap when you get there. You can threaten to walk with the check if you have any problems and retract the sale via AMEX...they'll work with you because they know how sketch dealerships are.