Is this happening only during this pandemic or used to happen before too?
Could be due to a variety of reasons ranging from hot stuffy car due to avoidance of AC ( if it's a cab), relative oxygen deficiency due to constant use of masks, anxiety or a combination of multiple reasons.
Systematic evaluation to delineate the cause is needed.
Next Steps
contact a psychiatrist for evaluation.
Health Tips
try practicing mindfulness and diaphragmatic breathing during these journeys. that can be a good practice to start with