my (late) 2 cents:

I lent my van to my brother-in-law and family, and they came from
Pennsylvania for an unaffordable dream vacation touring California
before the oldest son went off to college. They visited Death Valley,
the Sierra (north and south), Big Sur, etc.

My cost? A few extra miles and one small new dent. My reward, a
van-load of converts (5, to be precise). They still ask how 'bessie'
is, and followed my subaru engine conversion with interest, having
drove with original engine to 10000' ;)

That said, I won't lend the van to just everyone, and they were within
a day or so drive at any point in time. And I did a complete
maintenance + overhaul of suspect parts before they came out.