Who has told a buyer that what you have is not what they need?

I've had a couple of incidents where I sold a car to someone and gotten nasty calls from the buyer or a parent. Around 1997 I was selling an 83 Monte Carlo. Young guy called me, all excited about it and he was coming straight over with cash in hand. I gave him the address and he was there in about 10 minutes. Looked it over quickly, started the 305 and revved it up a few times before handing me the full asking price. I said he should take it for a ride at least, but no, he was all ready to go. I had done everything to make the car safe, front end, brakes, exhaust, tires, etc, so I was not concerned about it being a good car. He leaves my house with no plates or insurance, burning rubber around the corner. Next morning I get a call from his father screaming at me that the transmission is blown up and leaking on his driveway. I tried to get him to calm down and offered to look at the car, including doing the labor free if the transmission needed to be replaced. He continues to scream at me and threatened to take me to court. At that point I asked him if he had read the bill of sale, specifically the part that said sold as is where is, no warranty or guarantee. Never heard from him again.
A couple years ago I was selling my wife's old car, it had a few issues, which I disclosed in the ad. Was asking $500.00, the car ran and drove, but needed an alternator and the overdrive didn't work, so all that one had to do was use the lockout button on the shifter. Much like the Monte Carlo, a woman called, very excited to buy the car, I was very clear in my explanation of what was wrong with it demonstrated how to lock out o/d on the transmission and even decided to include a set of 4 winter tires, on rims with the car. A couple weeks later, she calls me screaming about the car and she wants her money back etc. I told her that the bill of sale stated that it was sold as is, where is, and reminded her that I had been upfront about everything that I knew was wrong with the car. She was adamant that she was going to sue me for the money plus the cost of repairs. I pulled out my copy of the bill of sale, highlighted the sold as is where is, no warranty or guarantee, took a picture of it, and texted it to her. That was the last time I heard from her.