How can I create alerts with symbols and sounds for a car HUD?

For my driving simulator, I am trying to create dynamic alerts with/without sound where the player will be warned if they are at risk of a head on collision. Similar to how racing games alert players that they are driving in the wrong direction, I would like this alert to appear in the HUD of the car. The camera viewpoint will be in first person of the driver for this simulator. Thank you for your help and time