"new" truck shopping

I've had some interesting experiences with dealers over the years and pretty much always found that when I stick to my own limits and expectations, and I am willing to walk away if I don't get what I want, the dealers will back down rather than lose the sale.
I had a realtor friend of mine just had his truck wrecked ( he was without a vehicle over 6 months before he could find one); I had to walk him through the dealerships, and the games they played after he got jacked around so many times, he called me not knowing what the heck to do!.... I mean some of the stuff they do is blatantly obvious if you're a car guy.... I told him crawl underneath and inspect everything you can (he's all worried about that carfax report ) I told em "that thang ain't nothing but a piece of paper bro" the one he liked (with the price he was willing to pay) was leaking underneath he said "it looked like it was from the back of the motor" I said "dude that's the rear main seal" so the dealership brought out their mechanic and he said "it's perfectly normal for those things to weep a little bit of motor oil.".... I get it if it's a 1976 chebbie or something like that Good Golly this was a freaking 5 to 7 year old Honda or some **** like that