Shinoda did make boss mustangs during the 90's, but i believe the car you are speaking of was the SVE Boss Mustang. That was a really cool car, it had a boss 429 engine and ran 10's in the quarter mile. But yes, it was made by a division of Ford called SVE - Special Vehicle Engineering
Those classic Boss Mustangs are at the top of my list of awesome cars. Also, that SVE Boss Mustang kicked as*. This new Shinoda Boss isn't all too amazing or spectacular like the classic Ford-produced stangs.