Have two cars.

The older of the two -- the 95 Chevy Cavalier -- I've been trying to
put as many miles on it as possible.  Whenever we're driving around
town we use the Cavalier and whenever there's an hour or two hour trip
I opt for the Cavalier.  The thing is starting to rust out and I figure
within a few years it will be unbearable so I might as well get as much
out of it as I can.

Because we're leaning so heavily on the Cavalier, we barely ever start
up the Toyota Avalon.  My wife will use it for grocery shopping and a
few errands around town when I'm at work, but that's about it.  Most of
the time it sits there.

I was wondering if these little, infrequent jaunts could damage the
Toyota.  I seem to remember someone -- friend, coworker...don't know
who -- saying that you don't want to buy a car from the stereotypical
little old lady who used the car only for grocery shopping because this
infrequent use damaged the engine.  How?  I don't know.  Is this a
myth, or does it have some truth to it?