I just went through something similar at my dealership buying a new Sierra AT4. I stopped in to look at what they had, mainly because they are local and their service department is exemplary.
They had just received a batch of AT4's so I had a few to pick from and when I looked at their web ad, were advertising a pretty aggressive discount off MSRP (pretty rare around here where most dealers are marking trucks up, what few they have).
I really liked the truck I drove and decided I would buy it, if they were willing to sell it to me for their loss leader advertised price. What a joke. These guys, most about half my age, tried every slimy trick in the book (actually a few, blatant lies, pretty bad), most in a very ham ****** way. I stayed very firm offering them their advertised price on the truck and got up and walked out three times before they finally gave up.
After triumphantly proclaiming I had a deal (just the deal they had advertised to get me sitting down in the first place), they brought me to another building to sit down with the "finance manage" who proceeded to try and sell me on all manner of add on's like extended warranty, a "pre-paid" service package, some sort of comprehensive theft protection package, a "dealer documentation" fee, etc. etc., etc. I had to stand up to walk out two times with the finance manager, and I was wasn't financing anything...
The most aggravating thing in the whole process was the amount of time it took. I was there for maybe 3 hours, on a purchase that should have taken 30 minutes all in.
In the end, I got the truck for what I was willing to pay and I suppose had these guys been trying to sell my truck to someone who hadn't seen all these tricks tried 20 times in my distant past maybe they would have made a few thousand more on the sale. I honestly thought all that stuff was pretty much dead 10 years ago.
The amazing thing to me is their service department is the best shop I have ever used on a vehicle. Very competitive pricing and extremely honest, to the point of telling me to defer things on my Yukon that I had brought up to my service writer, explaining it was something that could wait another year, maybe longer.
Good cop, bad cop, I guess.