Have had this problem , too. Gotta drive the cars or the calipers freeze up. Both my "spares" are in the garage now. Not sure it really helps as they get condensation with the temperature swings we see these days.
I am in constant battle to keep the vehicles moving or they do rust up bad.
The garage thing helps, but you are right they need to be driven. I have 2 cars and a pickup truck. It's expensive to keep getting the brakes done from lack of use. There are days lately that I just drive them down the road and back just to eliminate some of the rust. I hope it helps but......not sure in the end they look like crap. Then I look at cars next to me at stoplights and I have shinny rotor jealousy.
Can't imagine it is such a problem. When people move from the suburbs into the City, and park their car on the street for the first time, they're sure they'll be driving every day.
Then they learn about our traffic jams, absence of available parking, and the cost of a City sticker and permit. So they let their car sit, and take transit, walk, ride a Divvy bike-share or call an Uber. Some cars out in front have been sitting in the same place all winter. But somehow, come spring, they'll be gone, apparently no worse for the long cold winter.
So many people just cannot imagine living without a car. I think it is a security blanket for them...as neglected and rusted out as it might become!
Yep it's an instant escape out of the city. I'd have one or two myself. But you really don't know how rusted they can get unless you ask someone.
Yeah, well those cars in Chitown are probably from this century, mine, are more.............retro.