Same here, always have the V5 handy to find/ clear up any issues. Before buying it or any bartering, have a good look around the vehicle. Then start it up and let it tick over, then look about for leaks/drips, then drive or get the owner to drive it. I have never shown anything to anybody regarding vehicle sales.
Once I went to buy a VT 500e motorbike from a bloke in Rutherglen (who had it advertised in his shop window) and it never had a battery, so he drives his mini moke beside the bike and jump starts it. 'Great' I said, 'can I test ride it' around the ground behind his photographic studio, he said 'ok' as I had left my girlfriend as collateral
. So complete with his motorcycle and jump leads and the battery from his beach ride in the top box, I drive around the car park. 'wow' I said it pulls really good, I didn't have a crash helmet on as it still had
a sidewinder bolted on. So we agreed a price that we were both happy with, I walked to the nearest ATM, came back, and he asked me to then drive his mini moke back inside his studio. Ok bud, and as I was carefully reversing it, he told me 'your taking to long' It didn''t have any mirrors. So he jumped into his moke and reversed it into the edge of one of his rollers shutters, and bent it all.
I did give him a help to fix it so his shutter would close though. Came back the next morning with a battery and drove it away (after taking the sidewinder off)