What is the ruling on praying before the due time out of necessity while traveling or working in a European country, and is it permissible to pray while sitting in a car after the due time, and is it permissible for one to combine the two prayers?

For the validity of prayer, the time must have entered. Thus, whoever prays before the time has entered, their prayer is invalid. There is no difference in this regard between lands of Islam and lands of disbelief. Prayer can be performed in any pure place on earth. It is not permissible for a resident to combine prayers except in cases of extreme hardship. It is permissible to combine two prayers during rain. Performing obligatory prayers while seated in a car is not permissible except in cases of utmost necessity. Muslims must observe prayers at their prescribed times without shyness.