TIFU. Nearly put an old man through the windscreen of the car while on a test drive.

Actually happened yesterday still dealing with the aftermath. Been looking for a little automatic car for my partner for a while, a cheap banger that starts and stops. Found an ad on Facebook marketplace for a Suzuki wagon £500. Obviously gonna be crap but hey it had MOT and was cheap enough to spend money on repairs it might need. Met this old boy at his house, he drives us out and I drive back, partner in the back. He's chatting shit the whole drive, proper del boy he's 64 years old. I'm trying to listen to the engine and gear changes, he won't shut up. I drive it back seems alright. Just as we are nearing the turn to his house he is still blathering on and I miss the turn for his road. He says 'quick pull in here and do a U-turn'. Well, I drive a manual normally and in my haste fully stamped on the brake pedal looking for a clutch. Old boy is not wearing a seatbelt. Old boy has bad legs from diabetes. He is smashed into the dash and his head hits the windscreen at around 25mph. The friendly old man act slips, understandable, he shouts. 'What the fuck did you fucking do, what is fucking wrong with you?' His eyes were bulging I actually thought he was going to choke me. I stammer that I was so sorry and asked if he was alright, he says 'Fuck off I'll walk back to the house'. Gets out, slams the bangers door so hard the car rocks and hobbles his way back the house. I am shook, my partner just stares at me mouth open. We trundle back to the house. He has gone inside and shut the door. We stay in the car not saying a word for about 2 minutes. He reappears and I say sorry again he doesn't even look at me, he asks my partner if she likes birds, and all of a sudden we are in his house and she is holding his fucking African Grey parrot. Then he says he has another surprise, follow him into the back garden. I honestly thought he was going to kill us both. No, he introduced us to his tortoise named Gazza. At this point I am overwhelmed by guilt and confusion, we go back to the kitchen and he asks for us to lay the money on the table. I snap to some sense and meakly ask my partner if she actually wanted the car, del boy glares at me, she sees this and says yeah it seems fine. He says he doesn't have the logbook. Right. Guilt made me put that money on that table. Well due to me nearly splitting his head open I didn't get a chance to look under the hood. Get the car back to the house and I look under the hood. For fucks sake. Absolutely no engine oil. Zip. Dry as a fucking nun. The engine casing is absolutely soaked in oil. The car has pissed itself at my horrendous driving. Start it up this morning the most horrendous squealing coming from the transmission. Blue smoke pouring out the back. Honestly don't know whether to scrap it or burn it. Turns out he buys loads cars from auction sites and sells them on to idiots like me.

TL;DR test drove old mans automatic car, stamped full force on the brake looking for the clutch, smashed him into the windscreen because he wasn't wearing seatbelt. Bought car from guilt turned out to be complete scrap.