They may request your personal details, but you’re not obliged to show your passport or ID card.
During the spotcheck, they are permitted to check whether the vehicle is roadworthy, but they are not allowed to go through your bags or vehicles unless they present a search warrant.
Sometimes they will use small tricks to gain a quick peek in the boot of a vehicle e.g. ask to show that you are carrying a warning triangle or a first aid kit.
You are permitted to lie to the police provided you do not incriminate another person. A good example is when you drank abit and know you are well below the drink-drive limit. If you tell the truth, you may provoke the officers into undertaking a more thorough and time consuming examination which is unnecessary.
One important thing to remember is that you have the right to remain silent. If you attempt to appease them e.g. I’m sorry, I know I was speeding, it shows that you knowingly committed the offense and is considered an admission of guilt.
Traffic police might once again use little tricks to get a driver to admit their guilt. For instance, the officer might casually ask why you think you have been stopped. In this situation, it is advisable to say that you do not know to avoid any incrimination.