HID headlamps designed, engineered, manufactured, and certified or type-approved as HID headlamps are legal everywhere. "HID kits" and "projector retrofits", where HID bulbs are installed in headlamps not originally designed to accept them, are unsafe and illegal everywhere.
Yes.
yes is legal
no
Yes.
Depends, HID KITS are not legal anywhere in the US, they violate US DOT law. HID lights that come factory with a proper projector designed with HID in mind (higher end cars; Audi, Mercedes). Practically, if you aim the HID lights down, as to not blind other drivers, its unlikely that a cop will pull you over, as they can't really tell if your lights stock or an addon kit.
No, there are no such things as "hid lights".
The older BMWs do not have HID lights
No, generaly the car lights cums with elargins if we want HID lights we can install...it
Don't. "HID kits" are widely available, but they are (all) illegal and dangerous. The only legitimate/safe/legal HID conversion is to install complete HID headlamp assemblies designed, built, tested, and certified as such. Halogen headlamps mustuse halogen bulbs.
HID lights are generally illegal, and the name is a clue as to why, These are 'high intensity discharge' lights and they can blind any cars coming toward you. There are conversion kits sold that are supposed to prevent this, but you should be careful retrofitting your car to stay legal.
Yes, HID lights need a ballast.
There are two ways to do this:Replace the entire light unit with a HID light unit compatible with the car, if one is available.Use an aftermarket HID conversion that fits standard bulb sockets, and adds HID bulbs and a ballast unit.HID bulbs require a ballast unit to generate the high voltages required, so are not a direct replacement. In most HID kits, the power can be taken from the existing lighting power supply, so the lights operate as normal.HID conversion kits are not road legal in some countries.