Volkswagen: Old Beetle, new TDi engine, car electrics, boxer engines

Question
I was just wondering if it would be possible to put a diesel engine from a New Beetle into an Old Beetle and if so, how involved of a process would it be as far as changing out other parts besides the engine.

Answer
nothing is impossible, but as far as challenges, this is a hard task. you would need to change the fuel tank, fuel lines, get a wiring loom made up to connect the electrics of the engine to the exisisting car electrics. (ps, this is assuming the car is 12v and not 6v). also you need to fit engine ecu, get a custom exhaust designed and made. the old gearbox would not couple to the new engine, so would need adapting or replacing. the rear subframe would almost definitely need altering to take the engine as beetle engines are flat 4 cylinder boxer engines and new diesel engine sit vertical and are in line 4 cylinder. the drive shafts would need to be engineered to fit and also take the extra load. This is just some of the obstacles you would come across. i would not even attempt this task myself.