It is very common among to perform vehicle pooja. This is done to avoid accidents and to usher in profit. Here is a mantra for vehicle puja. The mantra should be chanted after offering prayers to Ganesha.
Mantra For Vehicle Pooja
ॐ नमो भगवते शक्ति रुद्रया मारुती नमो नमः
Om namo Bhagavate Shakti Rudraya Maruti Namo Namah
ॐ नमो भगवते शक्ति रुद्रया मारुती नमो नमः
Om namo Bhagavate Shakti Rudraya Maruti Namo Namah
The vehicle should be parked facing north, northeast or east for chanting the mantra. Water should be sprinkled on the vehicle three times. A diya should be waved around the vehicle. The vehicle should be adorned with flowers. A coconut should be smashed in front of the vehicle. A sweet should be kept on the vehicle and later it should be given to a cow.