To answer a couple questions - I hadn't really heard of Truecar a couple months back when I was shopping. I suppose the ads were out there but just hadn't caught my eye/ear. It seems they've really ramped up in the last couple months - radio/TV/billboards.
I went through the Costco auto program which is IMO the best way to go by far. The dealership I was working with was a "no haggle" pricing type. Prices posted on the windshield are the absolute lowest you'll ever get. The salesmen told me it's the same price he'd pay for the truck as an employee (yeah, right).
Anyway, this lowest possible price for my truck was 41,400 - with the Costco program I got it for 39,700. No haggling, no problems.
If I were shopping today of course I'd check out the price on Truecar while comparing. I also now realize my experience with MSRP vs actual price might be different with an American truck vs some other types/brands of vehicles.
For those of you flame throwers check out Truecar vs. Costco and let me know how it works out.