Their job is to lie. Car buys have to deal with it.
Everytime they say "This is all we can do", they mean "There's something else I can do", otherwise they wouldn't say it.
If a salesman says "I'll ask our finance expert to talk to you", he means "I'm not professional enough to make finacial lies, he's expert on it".
Everytime they say "I'm working in this area for over ten years, trust me", they mean "I've been lying for over ten years, don't try to pick my flaw".
I just experienced these guys for the first time and this is what I was taught. Good luck for car buyers.
I'm almost certain you will not find anything useful here in this blog.