I have been a "ride along" with friends who wanted to inspect an item for sale, and met the seller in a Walmart parking lot. Significant cash was involved both times, and both people asked me to come along, with my Auto Ordnance "Pit Bull" .45 ACP., as an "observer".
What you DON'T want to do is meet a stranger on a lonely road, or at night, or alone. We had an incident here a couple years ago where a middle aged, retired couple met a supposed seller of a classic car, alone, to buy it. They had saved for years to get just that model car, but were both murdered on the spot, and their cash taken. Caveat Emptor, in another light.
SRH