When I got my first job offer coming out of ISU, I went right out and bought a brand new car. I got a brand new Altima from Willis in DSM. The salesman took me back to his office to "finalize the contract." I was 23, this was my first time buying a car, and I did not bring any backup.
He tried to sell me on extended warranties and I kept saying no. Finally, he said "Look, I get $100 in commission to sell you the extended warranty." He then pulls out a $100 bill from his wallet. He said "I'll give you this right now if you'll buy the warranty, that's just how much I believe in it."
In addition to being incredibly unethical, I'm pretty sure that was illegal.