What is the ruling on praying while sitting in a car due to fear of the cold, given the absence of warm places for prayer except taverns or restrooms, during a journey that lasts eight or ten hours?

It is not permissible to pray in the bathroom, based on the Prophet's (peace be upon him) saying: "The entire earth has been made a mosque, except for the graveyard and the bathroom." If the time for prayer arrives and it is not possible to perform it except in a bar, there is no harm in that, provided you feel secure and pray in a clean spot within it.