Answer: a 3-D printer
Classic Motor Cars, a car shop in the UK, used a 3-D printer to manufacture missing or irreparable parts to a one-of-a-kind Pininfarina-bodied XK120 Jaguar. This, the rarest Jaguar in existence, was built in 1954 and took the Classic Motor Cars team 6,725 hours to restore piece by piece.
They did this by carefully photographing every inch of the car as they slowly disassembled it, and then used those photos — along with ones taken during the car’s lifetime — and a 3-D printer to create new replacement parts for those that were either missing or damaged beyond repair. Since glass can’t be printed on a 3-D printer (yet), the missing rear window was reproduced using 3-D-scanning technology.