They are Buddhas, you might look on the internet, although I’m not sure you will be able to find the ones like most taxi drivers and myself have. I think you mean the small gold ones with a glass (usually plastic) type case around the Buddha. They are very easy to get in Thailand, but by law, images of the Lord Buddha are prohibited from being taken out of Thailand , except by special permission from the government, but many people do without any problems.

Hi, many Thais like to put charm or charms in their vehicles, to ward off bad luck while driving or for personal protection. Depending on individuals, this charm/s can be Buddha or priest from certain province or temple. Whoever is the person personal guardian.

If you want, you do not buy them, but bring one back with you, as Buddha cannot be bought. Usually in any of the Thai temples or in its vicinity, you can find shops offering these statues. It would be advisable that you ask who might be suitable for you to bring home with you or put in your car. They each have individual strength and purpose, if you believe in them.