I would say maybe try the showrooms near Jail Chowrangi. They sell these imports and as we all know by now most of these cars arrive damaged and then get repaired so they might help you import parts or even have some about.
Or you can go to Ayesha Manzil, FB Area. Shops near there do some crazy repairs on cars that you would otherwise consider major write-offs. Ofcourse the issue of parts remain but I am sure someone who repairs insurance cars for a living will know where to look.
Best of luck