The Lego professional Fernando over at Sheepo's Garage is an absolute beast when it comes to creating replica vehicles. His latest creation is this 1:8 scale 2014 Ford Mustang Shelby GT500, custom built using 3500 parts and 5 motors. Fernando doesn't use kits for his builds. All of his creations use geniune Lego parts but the designs are his own and they are insanely accurate. The replica has functioning doors and interiors as well as suspensions, a drive train, working steering wheel and pedals, gear indicator, and various other features you would not expect from a Lego build.
There are a few instruction posts on his site, but unfortunately Fernando doesn't sell his creations or make copies. If he were to sell them, we could only imagine what the cost would be considering the amount of work that goes into each build. See the replica in all its glory in the video below: