I think that the real issue is that a car, much like a home is one of the relatively few things in this world that Americans (for the most part) will ever negotiate the price of. In the US most things traditionally "cost what they cost". You decide what you want to buy, you go to where they sell it, and you pay them the price that they have on the price tag if you want it bad enough and/or think it is worth the asking price. Relatively few people in the US negotiate daily and for most of them it's not a comfortable experience. Most people don't have a comfortable understanding of the process and are worried that they're being taken advantage of when they settle on a price. The process doesn't do much to help get past this fear. The last time I bought a car I did it online. I was looking for a 2006 Pontiac GTO and went to Pontiac's website where I searched for one in Texas and Louisiana. I found them all, assembled all their email addresses for their online sales department, and sent them the same email. Basically "I want a 2006 GTO, I'm going to pay 18% off sticker, I don't care what color it is or whether it is an automatic or manual transmission (there were very few options on that car). Please contact me if you want to move a car right now. I have my own financing lined up. Thank You".
I got a bunch of replies. Most said nobody would make that deal and three said they had a car they would sell me for that deal. I picked one (a silver one in Bastrop Texas) and drove there from Houston with my wife to pick it up. I was in the dealership for about 45 minutes.