More about #GRIDLIFE here! http://www.grid.life/ We have had good experiences with Hennessey in the past, and the engine these guys have built for this new 2015 Mustang GT is no exception: it's a monster, capable of propelling the new Mustang GT to a proven 207.9 MPH. Thing is, this particular CUSTOMER car only has the engine. The rest is bone stock, down to the brakes and tires. And it's an automatic transmission. An ideal track rat, this is not. But we go on the track anyway!