The vehicle we were in did have a shotgun rack, but someone mugging him was a pretty low possibility. It was a restored truck (very nice old Ford). It would have to be some stranger from out of area. Calling some dumbass's uncle for starting trouble is still a pretty effective crime solving technique in large parts of the US.
[edit] where the heck do you live that muggings are commonplace?
It wasn't about privacy, it was just buying a truck. I never said it was about privacy. Hell, the DMV knew about the truck about 40 minutes after he bought it. The seller reported it as income[1]. This had nothing to do with privacy or fraud, and his bank wouldn't let him write checks for over $5,000 and he sure wasn't going to pay some fee for a certified check that the guy selling the truck wasn't going to take anyway.
We didn't see it as a risk. It was just a bit odd to have 150 $100 bills. Puts a little weight into the cost of what you're going to buy. Good thing he bought it too as his old truck (which I drove back, that's why he brought me not as some security) needed about $3,000 in repairs. He sold it to a farmer who did the repairs himself. My friend kept the truck for about 2 decades.
1) I remember his receipt pad. It was styled like something I imagine came out of a Dickens story. He basically bought wrecks and stuff in garages and restored some or built mods out of others. Pretty good retirement gig.
I'm kind of surprised that the bank had that much cash on hand. I've known people that saved up enough to pay off their mortgages (less money than you were talking about), when they went to withdraw the cash from their savings to take to the bank that held the mortgage, the first bank was down to giving them 20s.
Deal with a lot of farmers and your bank has reason to keep a bit of cash on hand. 15k really isn't that much to them. They did count it twice (unwrapped the paper around the groups of bills).
[edit] where the heck do you live that muggings are commonplace?