When the next generation Cadillac CTS-V hits the streets later this year, it will have 640+ hp and a top speed of nearly 200 mph. To the team at Hennessey Performance Engineering (HPE), this is a good starting point. The company plans to pick-up where they left off with the last gen CTS-V by producing the world’s fastest 4-door sedan: The Hennessey HPE1000 Twin Turbo CTS-V.