From the dealer. Some dealers have the equipment to cut keys and can copy your existing key on the spot. Some don't have the equipment.
To get a VIN cut key, you will need proof of ownership such as matching driver's license and registration. A new key will arrive in about 2 days.
82 300D Euro
12 Honda Pilot
14 Tesla Model S
Former MB: 86 190E 2.3, 87 300E, 80 240D
Chain Elongation References