Former prime minister Nawaz Sharif records statement in Toshakhana corruption case; case also involves Asif Ali Zardari and Yusuf Raza Gilani; allegations of receiving luxury vehicles at discounted prices; no record or documentation of vehicle given to Sharif; court adjourns hearing till December 20; accused retained vehicles against nominal payment; non-bailable arrest warrant issued for Sharif in June 2020; Sharif surrendered before court last month after four years of exile.