Idols of God- Most people keep small idols of deities in their car, but according to Vastu Shastra, keeping a small idol of Ganapati is most auspicious. Lord Ganesha is related to Ketu. It is believed that Ganpati protects from accidents and removes all obstacles in the way. Similarly, putting an idol of Lord Hanuman swinging in the air in the car is also considered auspicious. They protect from calamities and remove bad effects.
http://en.myjyotish.com/en/photo-gallery/astrology-blogs/vastu-tips-2022-bring-home-these-5-things-home-to-avoid-money-crunch
