What you're noticing right now
If you've been looking at a used car in the last few weeks, you've probably noticed the lots getting busier. That's normal this time of year in Brooklyn. People who spent the summer relying on the subway or a bike start thinking about the commute to Long Island relatives, weekend trips upstate, or just not wanting to stand on a windy platform in January. The problem is that a used car bought in October or November has to survive a New York winter almost immediately, and a lot of the wear that matters doesn't show up on a test drive around the block.
Brooklyn winters aren't brutal by national standards, but they're wet, salty, and hard on a car that's already a few years old. Rock salt on the Belt Parkway and every side street does real damage to brake lines and exposed metal. Street parking means the car sits outside in freezing rain and slush for hours at a time, not tucked into a heated garage. None of that is dealbreaker weather, but it means a car with hidden problems gets found out fast.
The battery and the cold start
A used car's battery is one of the easiest things to check and one of the most commonly ignored. Ask when it was last replaced. Most batteries last three to five years, and a battery that's already marginal in October often won't start a car at all once temperatures drop into the 20s. If you can, have the seller start the car cold, first thing in the morning, before the engine's been running. A slow, labored crank is worth asking about.
You can check terminals yourself for corrosion, a white or greenish crust around the posts. That's a cheap fix if it's the only issue. But if the seller can't tell you the battery's age or there's no service record, that's the point to have a mechanic run a proper load test before you commit.
More on this from What To Check On A Used Car Before Winter.
Tires that can actually handle a Brooklyn winter
Look at the tread depth, and don't just eyeball it. The penny test still works: insert a penny into the tread with Lincoln's head down, and if you can see all of his head, the tires are too worn for wet or icy roads. This matters more here than it might elsewhere, because Brooklyn streets go from dry to icy to slushy to dry again in the same week, and worn tires lose grip fast in that kind of switching.
Check all four tires, not just the two you can see easily. Uneven wear front to back or side to side can point to alignment or suspension problems that a quick look under the car won't reveal. That's a job for a mechanic, not a driveway inspection.
Rust, especially underneath
This is the one that catches people off guard. A car that looks clean on top can have serious rust underneath from years of salted roads, especially if it spent previous winters parked on the street rather than in a garage. Get down and look at the wheel wells, the frame rails, and the exhaust system. Surface rust on a bumper is cosmetic. Rust that's eaten into the frame or the brake lines is not, and it's expensive to fix if it's fixable at all.
You often can't see this from the driver's seat or even from a quick walk-around. If a car has spent its life in New York or New Jersey, ask directly about its parking history and get it up on a lift before you buy. Any mechanic can do this in twenty minutes, and it's worth the trip before winter, not after.
Heat, defrost, and the parts you won't test until you need them
A used car's heater and defroster rarely get checked on a test drive because most people don't think to turn them on in September. Run the heat on high and see how long it takes to warm up. Turn on the rear defroster and both side mirror defrosters if the car has them, and make sure they actually clear condensation instead of just glowing warm to the touch.
These are cheap to check and annoying to fix later, especially once the cold actually arrives and every mechanic in the neighborhood is booked solid with the same complaint. If something doesn't work right when you check it in the seller's driveway, don't assume it'll sort itself out once the weather turns. Get it looked at before you sign anything, not after the first frost.
Where to stop guessing and call a mechanic
A homeowner or buyer can reasonably check the battery's obvious signs, the tread depth, the visible rust, and whether the heat blows warm. What you can't reliably judge on your own is what's happening inside the brake system, the condition of belts and hoses you can't see, or whether the rust you spotted is cosmetic or structural. That's where a pre-purchase inspection earns its cost. It usually runs a couple of hundred dollars rather than a couple of thousand, and it's the difference between finding a problem in a warm shop in November or finding it on the Belt Parkway in a January storm.