In Missouri,

Apartment complex throughway and parking lot (no carports or garages) is littered with potholes several inches deep, enough to ruin your undercarriage, transmission, and alignment if you hit one.

One deep pothole every few feet, littered with several other potholes. It looks like a battlezone. Some potholes go through to the ground (dirt) or sub-pavement beneath.

It has remained this way through last autumn, winter, spring, and now summer.

What can be done? Is this reasonable? Is this legal? Do they have a responsibility to maintain the parking lot to reasonable repair? Can I call anyone or a city advocate to pressure them into making repairs to this "utility" or "ammenity" that also affects transportation and private property (IE my car!)

It might be covered by local Codes. I'd start by asking the landlord if and when he plans to make repairs, and if he is not cooperative I suggest calling your local Code Enforcement people and ask them to do an inspection.

It will depend on who owns the parking lot, if this is a government owned (city or county) housing project, often the city itself is responsible for the parking lot on these.

If the drive into the parking lot is really a city alley or street, it still could be the city.

If the drive is owned by the apartment complex they are responsbile to keep it up. The exact requirement for upkeep may vary by code ( or in some cities lack of code)