Detroit.

The car company Henry Ford had begun before the current Ford Motor Company had failed and gone bankrupt without having built a single car. The bankers that had financed it sent in Henry Martyn Leland to estimate the value of what could be sold off to try to make up for the losses. But Leland found plans for a car designed by Ford but had never been built. He proposed to the bankers that instead of selling off the assets of the failed company that the company be reorganized and that it first product be the Ford designed car in those plans.

Thus the first Cadillac car was a Ford designed car that Ford never built, equipped with an improved engine designed by Leland.

Varies by model. There are different models and options packages available, and the costs vary with them.