To buy a car, you must walk to Spencer, who is standing in the building near the entrance. Press 'F' to interact, and you'll be able to talk to him about buying a car. There will then be a car customization screen, and you can customize your car with various accessories and colors. You can then purchase it, and you'll be able to access your car in the parking lot.
The exterior of the building has many windows looking into the building, with over 5 windows on the front, and many windows on the left side. There are no windows on the back or right. The outer walls of the building are made from light grey concrete.
The interior of the building has a dark grey marble texture for flooring, and the other walls/roof are also light grey concrete, similar to the exterior. As you walk in, you will see Spencer at his wooden desk, and then to your left you will see a car, which is what you will customize to your needs after speaking to Spencer.
Images coming soon-- my ROBLOX isn't working right now.