Earlier quoted context omitted.
One of the world's most complex engineering challenges, filled with tens of thousands of highly engineered parts and tens of millions of lines of code, with per unit pricing ranging from $10k to $100k+, is a "commodity"? The term "commodity" typically refers to products that feature little to no differentiation between each other. It means you could largely "throw a dart" to pick one, and you'd be no better or worse…
the same model car across different dealerships is a commodity. that's why carwoo was great, it helps you run a commodity auction to get the best price.
The sales staff are not competing against other dealerships of the same maker. They are competing against other makes. They are really selling you the brand.
Having said that, I think it's stupid that once you know the exact make and model you still need to deal with the sales staff. At that point, just give me the best price you have. You know what it is, you know what your competitors are doing. Why are we still talking?
Also, I don't know if you've noticed, but the landscape is changing. One of the big changes is that much more of the salesperson's income comes from salary and not commission. This is good. This means less sneaky tactics. Also, lots of dealerships now have an Internet department which will give you a quote online that is likely pretty close to your final offer. It's still worth trying to haggle, but lots of them don't have time for this: they simply give you an offer that's low enough to where you might actually just take it.